Physics Calculators
Physics calculators for motion, energy, and forces
Electromagnetism
Coulomb's Law CalculatorElectromagnetismFind the electrostatic force between two point charges with Coulomb's Law. Enter any three of the charges, distance, and force to solve for the fourth, with electric potential energy, attraction or repulsion, and the inverse-square curve.
Acceleration of a Particle in an Electric Field CalculatorElectromagnetismFind the acceleration of a charged particle in an electric field with a = qE/m, or solve for the charge, field or mass. Also builds the field from a voltage and gives the particle's speed, distance and kinetic energy.Mechanics
Work CalculatorMechanicsSolve for work, force, displacement, or angle from W = F x d x cos(theta). Mix metric and imperial units, handle positive, zero, and negative work, and convert work to power or to a final speed.
Wing Loading CalculatorMechanicsFind wing loading from aircraft weight and wing area with WL = W / S, and solve for any of the three. See the force-basis figure in N/m2, estimate the stall speed, compare against reference aircraft, and get the wing cube loading for models.
Wheel Rate CalculatorMechanicsFind wheel rate from spring rate and motion ratio, or solve for either one. Includes ride frequency, pounds-per-inch output, and a motion-ratio sensitivity chart.
Wheel Flop CalculatorMechanicsCalculate the wheel flop factor from trail and head angle, f = trail x sin(theta) x cos(theta). Solve for any of the three, build trail from wheel size and fork offset, and see the steering drop and self-steer torque.
Velocity CalculatorMechanicsCalculate velocity three ways: average velocity from distance and time, or final velocity under constant acceleration from time or from distance. Solves for any field and reports momentum and kinetic energy.
Torque CalculatorMechanicsSolve for torque, lever arm, force, or angle from tau = r x F x sin(theta). Mix metric and imperial units, convert torque to power, and see the torque-vs-angle curve.
Strouhal Number CalculatorMechanicsCalculate the Strouhal number from vortex shedding frequency, characteristic length, and flow velocity with St = f L / U, and solve for any of the four. Check for vortex-induced resonance, estimate the cylinder value from the Reynolds number, and compare against typical Strouhal numbers.
Static Thrust Load CalculatorMechanicsFind the static thrust load capacity of pins, bearings, and fasteners from yield strength and contact area with Ft = Sy x As, and solve for any of the three. Add a safety factor for the safe working load, check an applied load, and compare materials.
Spring Rate CalculatorMechanicsFind spring rate, force, or travel with Hooke's Law, or design a coil spring from its wire diameter, coils and material. Combine springs and see the stored energy.
Specific Weight CalculatorMechanicsCalculate specific weight (unit weight) from weight and volume or from density and gravity. Solve for any variable, get the density and specific gravity, and read hydrostatic pressure at depth. Units in N/m3, kN/m3, and lb/ft3.
Solar Lift Coefficient CalculatorMechanicsCalculate the lift coefficient for solar chimney turbine blades from lift force, air density, wind speed, and planform area. Solve for any variable, plus dynamic pressure, lift loading, wind power, site-altitude density, and the lift-to-drag ratio.
Simple Pendulum CalculatorMechanicsFind the period, frequency, and angular frequency of a simple pendulum from its length and gravity. Solves in every direction, with a length chart, a large-amplitude correction, and a period comparison across other worlds.
Rate of Turn CalculatorMechanicsFind the rate of turn of a banked aircraft from its bank angle and true airspeed, and solve for any of the three. Adds load factor, the time for a 360, standard-rate bank angle, turn radius, accelerated stall speed, and heading-change timing.
Range of a Jet CalculatorMechanicsEstimate a jet aircraft's range with the Breguet equation. Enter cruise speed, TSFC, lift-to-drag ratio, and weights to find still-air range, then apply a mission allowance and wind for a real-world planning estimate. Leave any field blank to solve for it.
Pressure CalculatorMechanicsCalculate pressure from force and contact area with P = F / A, and solve for any of the three. Convert between gauge and absolute pressure, read the result in kPa, bar, psi, atm, and mmHg, and compare it against familiar pressures.
Power Required at Altitude CalculatorMechanicsFind the power an aircraft needs for level flight at any altitude from the aerodynamic power equation. Solve for power, air density, true airspeed, area, or drag coefficient, with an ISA density helper and a constant-lift climb projection.
Power CalculatorMechanicsCalculate power from work and time, force and velocity, force with distance and time, or torque and rotational speed, and solve for any value you leave blank.
Potential Energy CalculatorMechanicsCalculate gravitational potential energy (PE = m g h) or elastic potential energy (PE = 1/2 k x squared), or solve for the mass, height, gravity, spring constant, or displacement. Includes weight, impact speed, the energy-exchange chart, and a compare-across-worlds table.
Physical Pendulum CalculatorMechanicsFind the angular frequency, frequency, and period of a physical pendulum from its mass, pivot distance, and moment of inertia. Solves in every direction, with the equivalent pendulum length, a large-amplitude correction, and a shape helper for the moment of inertia.
Neutral Point CalculatorMechanicsFind an aircraft's neutral point, static margin, and recommended centre of gravity from wing and tail geometry. Also gives the mean aerodynamic chord, tail volume coefficient, wing loading, and stall speed.
Momentum CalculatorMechanicsCalculate momentum from mass and velocity, or solve for mass or velocity. Includes kinetic energy, conservation of momentum in elastic and inelastic collisions, and relativistic momentum.
Mechanical Trail CalculatorMechanicsWork out mechanical trail and ground trail from tire radius, rake angle, and fork offset, and solve for any of them. Adds self-aligning torque, a tire-size-to-radius helper, a trail-vs-rake chart, and a vehicle benchmark.
Mass CalculatorMechanicsCalculate the mass of an object from its density and volume with m = ρV, or solve for the density or volume instead. Reports the weight under any gravity, in any unit from milligrams to tonnes.
Longitudinal Static Stability CalculatorMechanicsCompute the pitching-moment coefficient, tail volume coefficient, neutral point, and static margin from aircraft geometry, then size the tail or find the aft CG limit for a target stability margin.
Lift Force CalculatorMechanicsCalculate aerodynamic lift force with the lift equation. Solve for lift, speed, wing area, density, or lift coefficient, plus dynamic pressure, lift-to-drag ratio, glide angle, and stall speed.
Lateral Static Stability CalculatorMechanicsFind the rolling-moment coefficient from the sideslip angle and the roll stability derivative (the dihedral effect), solve for any variable, estimate the derivative from wing dihedral and position, and scale it to a real rolling moment.
Lateral Acceleration CalculatorMechanicsFind the lateral acceleration and g-force of an object on a curve from its speed and turn radius, and solve for any of the three. Adds cornering force, banking angle, required grip, max cornering speed, angular velocity, and a speed-sensitivity chart.
Kinetic Energy Absorbed by Brake CalculatorMechanicsCalculate the kinetic energy a vehicle's brakes absorb when slowing from one speed to another, and solve for mass or speed. Adds brake temperature rise, force, power, regenerative braking, and repeated-stop heat.
Kinetic Energy CalculatorMechanicsCalculate kinetic energy from mass and speed with KE = 1/2 m v squared, or solve for the mass or the speed. Includes momentum, the work-energy theorem, equivalent fall height, and the relativistic correction.
Jet Endurance CalculatorMechanicsSolve the Breguet jet endurance equation for any variable. Enter TSFC, lift-to-drag ratio, and weights to find how long an aircraft can stay aloft, or leave any field blank to solve for it.
Impulse CalculatorMechanicsCalculate impulse from force and time or from mass and velocity change, and solve for force, time, mass, or velocity. Includes momentum, acceleration, and kinetic energy.
Gravitational Force CalculatorMechanicsCalculate the gravitational force between two objects with Newton's law of universal gravitation. Enter any three of the masses, distance, and force to solve for the fourth, with potential energy, per-mass acceleration, escape velocity, and the inverse-square curve.
Free Fall CalculatorMechanicsCalculate free fall time, velocity, and distance from any one of them, with selectable gravity, impact energy and momentum, and a solar-system comparison.
Force CalculatorMechanicsCalculate force with Newton's second law F = ma, or solve for the mass or acceleration instead. Also finds the acceleration and force from a change in velocity, in any unit from newtons to pound-force.
Flexure CalculatorMechanicsSolve the flexure formula sigma = M y / I for bending stress, moment, or section size, with rectangular and circular shortcuts, a 3 and 4 point bending-test mode for the modulus of rupture, and a deflection check.
Elastic Potential Energy CalculatorMechanicsCalculate elastic potential energy stored in a spring with U = 1/2 k x squared, or solve for the spring constant or displacement instead. Reports the spring force and works in any unit from joules to calories.
Driveline Torque CalculatorMechanicsCalculate wheel torque from engine torque, transmission and final drive ratios, and driveline efficiency. Add tractive force and road speed, or solve for any variable.
Drag Force CalculatorMechanicsCalculate drag force on an object moving through air or water with the drag equation. Solve for force, speed, area, density, or drag coefficient, plus dynamic pressure, power, terminal velocity, and deceleration.
Drag Coefficient CalculatorMechanicsCalculate the drag coefficient from drag force, density, velocity, and area. Solve for any variable, plus dynamic pressure, drag area, power, the Reynolds number, and induced and total drag.
Displacement CalculatorMechanicsCalculate displacement from velocity and time, from a change in velocity, from a constant acceleration, or without a time (stopping distance). Also finds average velocity, final velocity, and time, in any unit.
Disk Loading CalculatorMechanicsFind rotor disk loading from aircraft weight and rotor diameter (or solve for any of the three), with metric and imperial units, multirotor support, and a hover-power estimate from momentum theory.
Directional Static Stability CalculatorMechanicsFind the yawing-moment coefficient from the sideslip angle and the directional stability derivative, solve for any variable, estimate the derivative from the vertical tail, and scale it to a real yawing moment.
Density CalculatorMechanicsFind density, mass, or volume from the other two with rho = m / V. Enter any two values and the calculator solves for the third, with specific gravity, a float or sink read, and unit conversion built in.
Buoyant Force CalculatorMechanicsCalculate the buoyant force on a submerged or floating object with Archimedes' principle (F = rho V g). Solve for density, volume, or gravity, and check whether an object floats or sinks.
Buoyancy CalculatorMechanicsWork out whether something floats and by how much. Enter an object's volume and weight to get its net buoyancy, average density, submerged fraction and spare load capacity, size a helium, hydrogen or hot air balloon from the lift it has to produce, or turn hull dimensions into displacement and deadweight.
Bump Force CalculatorMechanicsCalculate the bump force on a vehicle's suspension from spring rate, displacement, damping coefficient, and vertical velocity. Solve for any variable and see the spring-vs-damper split.
Braking Torque CalculatorMechanicsCalculate disc-brake braking torque from pad friction, hydraulic pressure, piston area, and rotor radius. Solve for any value, with the clamp force and friction breakdown.
Boat Speed CalculatorMechanicsEstimate a boat's top speed three ways: Crouch's formula from power and displacement, displacement hull speed from waterline length, or propeller RPM from gearing and pitch.
Axial Loading CalculatorMechanicsCalculate axial stress, strain, and deformation of a member under tension or compression, with a material preset, a factor-of-safety check, and reverse solving.
Average Velocity CalculatorMechanicsFind average velocity as displacement over time. Solve for any variable, read it off a position-time graph, use the constant-acceleration midpoint, or add up a multi-leg journey.
Average Speed CalculatorMechanicsWork out average speed from distance and time, solve for any of the three, or add up a multi-leg trip. Get pace, unit conversions, and a per-leg breakdown.
Archimedes' Principle CalculatorMechanicsFind the buoyant force, fluid density, or displaced volume from Archimedes' principle, and check whether an object floats or sinks.
API Gravity CalculatorMechanicsConvert between API gravity, specific gravity and density at 60 F, with the crude oil grade, pounds per gallon, and barrels per tonne.
Anti-Squat CalculatorMechanicsFind the anti-squat percentage of a rear suspension from the line angle, rear-axle-to-CG distance, and CG height. Solve for any value, see the tuning curves, and read what the result means.
Anti-Dive CalculatorMechanicsFind the anti-dive percentage of a front suspension from the link angle, braking force distance, and CG height. Solve for any value, see the tuning curve, and read what the result means.
Angular Velocity CalculatorMechanicsCalculate angular velocity (ω) from an angle and time, a linear speed and radius, a period or a frequency, and read it in rad/s, RPM, rev/s and deg/s. Solves every method backwards too.
Angular Momentum CalculatorMechanicsFind the angular momentum of a spinning body from its moment of inertia and angular velocity (L = I omega), or of a point mass from its mass, speed and radius (L = m v r). Solve for any variable, work the moment of inertia out from a shape, apply the conservation of angular momentum, and read the rotational kinetic energy.
Angular Displacement CalculatorMechanicsFind angular displacement from a constant angular velocity (theta = omega t), from an initial angular velocity, angular acceleration and time (theta = omega-zero t + half alpha t squared), from an arc length and a radius (theta = s/r), or from a start and end angle. Solve for any variable, in radians, degrees or revolutions.
Angular Acceleration CalculatorMechanicsFind the angular acceleration of a rotating object from a change in angular velocity (alpha = (omega2 - omega1)/t), from a torque and a moment of inertia (alpha = torque/I), or from a tangential acceleration and a radius. Solve for any variable, and read the angle turned and the number of revolutions.
Angle of Twist CalculatorMechanicsCalculate the angle of twist of a shaft from torque, length, shear modulus, and the polar moment of inertia, or solve backward for any of them. Computes the polar moment for solid and hollow shafts plus the maximum shear stress and torsional stiffness.
Angle of Impact CalculatorMechanicsFind the angle of impact of a bloodstain from its width and length, estimate the height of origin, and read the spatter shape. Solve for any missing value.
Aluminum Weight CalculatorMechanicsCalculate the weight of aluminum bar, sheet, plate, tube, hexagon, and ring from the shape, alloy, and dimensions, with per-piece and total weight and an optional material-cost estimate.
Alfven Velocity CalculatorMechanicsFind the Alfven velocity of a magnetohydrodynamic wave with v_A = B/sqrt(mu0 x rho), or solve for the magnetic field or the plasma density. Builds the density from a number density, gives the relativistic speed, and times an Alfven wave across a distance.
Airfoil Thickness CalculatorMechanicsFind an airfoil's thickness ratio from its maximum thickness and chord, or solve for any of the three. Reports the nearest NACA thickness code, a profile drawing, and how it compares with real airfoils.
Acceleration Using Force and Mass CalculatorMechanicsFind the acceleration of an object from the net force and its mass with Newton's second law, a = F / m. Also solves for the force or mass, finds acceleration from a change in velocity, and reports the g-force, in any unit.
Acceleration Due to Gravity CalculatorMechanicsFind the acceleration due to gravity (g = GM/r squared) for any planet, moon, or custom body, plus the weight of an object and a free-fall drop on that world.
Acceleration CalculatorMechanicsCalculate acceleration from a change in velocity over time or from force and mass, with displacement, change in velocity, and g-force.Modern Physics
Schwarzschild Radius CalculatorModern PhysicsFind the Schwarzschild radius, mass, and surface gravity of a non-rotating black hole from any one of them. Also reports the event horizon's density and geometry, a compression comparison, and the Hawking temperature.
Fill Factor CalculatorModern PhysicsFind the fill factor of a solar cell from Voc, Isc, Vmp and Imp, or solve for any one of them. Includes the maximum power, the cell efficiency, the theoretical-maximum fill factor, and an I-V curve.
E = mc² CalculatorModern PhysicsSolve Einstein's mass-energy equivalence E = mc squared. Enter a mass to get its rest energy, or an energy to get the equivalent mass, with megatons of TNT, the Lorentz factor, and relativistic energy.
Bragg's Law CalculatorModern PhysicsSolve n lambda = 2 d sin theta for the Bragg angle, the interplanar spacing or the wavelength, with 2 theta conversion, diffraction orders, photon energy and d-spacing from lattice parameters.
Bohr Model CalculatorModern PhysicsCompute hydrogen-like energy levels, the photon energy, wavelength and frequency of an electron transition, and the radius, speed and period of a single Bohr orbit.Waves
Wavelength CalculatorWavesCalculate wavelength from frequency, from wave speed and frequency, or from photon energy, and work backwards from a wavelength to frequency and energy. Handles the refractive index of a medium, in any unit.
Frequency CalculatorWavesFind the frequency of a wave from its period, or from its speed and wavelength. Enter any two of frequency, period, wave speed, or wavelength and the rest fill in, with angular frequency and photon energy.
Angular Frequency CalculatorWavesFind angular frequency (omega) from frequency, period, rpm, or an oscillating system, and get the matching frequency, period, wavelength, and peak motion.Optics
Snell's Law CalculatorOpticsApply Snell's law of refraction to find the angle of refraction, the angle of incidence, or either refractive index, and solve for any of the four. Adds the ray deviation, critical angle and total internal reflection, the speed of light and wavelength in each medium, and Brewster's angle.
Brewster Angle CalculatorOpticsFind Brewster's angle from the refractive index on each side of a surface, or solve backwards for an unknown index from a measured polarizing angle. Includes the reflectance of each polarization, the 90 degree ray geometry, the critical angle, and a pile-of-plates polarizer model.
Binoculars Range CalculatorOpticsEstimate the distance to a target from a reticle reading in your binoculars or scope. Size-based and marine horizon methods, mil or MOA, with second focal plane correction.
Bathroom Mirror Size CalculatorOpticsFind the right mirror size for your bathroom vanity — width and height for a rectangular mirror, diameter for a round one, or the two-mirror layout for a double vanity.
Aperture Area CalculatorOpticsFind the aperture area of a lens or telescope from the diameter, or from a camera lens's focal length and f-number, with radius and light-gathering output.
Angular Resolution CalculatorOpticsFind the angular resolution of a lens, mirror, telescope, or microscope from the Rayleigh criterion, solve for wavelength or aperture, and add spatial, telescope, and microscope layers.
Angle of Refraction CalculatorOpticsFind the angle of refraction from Snell's law, or solve for either refractive index or the angle of incidence. Includes the critical angle, total internal reflection, ray deviation, and wave speed in each medium.Thermodynamics
Work of Turbine CalculatorThermodynamicsCalculate gas turbine power output and specific work from mass flow rate, specific heat, and the temperature drop across the turbine. Solve for any variable and layer in isentropic efficiency, net shaft output, and pressure-ratio estimates.
TSFC CalculatorThermodynamicsCalculate thrust specific fuel consumption (TSFC) from fuel flow and thrust, solve for any of the three, benchmark engine efficiency, and size mission fuel and cost.
Thermal Resistance CalculatorThermodynamicsCalculate thermal resistance of a layer with R = L / (k A) and solve for any of the four quantities. Find the heat flow from a temperature difference, convert to R-value and U-value, and compare materials.
Specific Thrust CalculatorThermodynamicsCalculate specific thrust from thrust and air mass flow rate with Is = F / m-dot, and solve for any of the three. Read the result in several speed units, recover the jet exhaust velocity and propulsive efficiency from a flight speed, and benchmark it against real engine types.
Solar Heat Gain CalculatorThermodynamicsCalculate the useful heat gain of a solar thermal collector with the Hottel-Whillier-Bliss equation, and solve for any of the seven quantities. See per-square-meter flux, efficiency, and the stagnation temperature, estimate energy and savings, and compare collector types.
Piston Displacement CalculatorThermodynamicsFind piston and engine displacement from bore, stroke, and cylinders, plus the volumetric flow rate, compression ratio, bore-stroke ratio, and mean piston speed. Solve for any input.
Mass Flow Rate CalculatorThermodynamicsFind mass flow rate from density, area, and velocity, or solve for any one of the four. Converts units and shows volumetric flow, pipe diameter, and the continuity result.
Mass Flux CalculatorThermodynamicsCalculate mass flux from density and velocity (G = rho v) or from a mass flow rate and pipe area (G = m_dot / A), and solve for any variable. Adds volumetric flow rate, equivalent pipe diameter, and the Reynolds number.
Ideal Gas Law CalculatorThermodynamicsSolve the ideal gas law PV = nRT for pressure, volume, amount, or temperature. Enter any three values and get the fourth, plus molar volume, gas mass and density, internal energy, and the pressure-volume curve, in any units.
Exit Velocity CalculatorThermodynamicsCalculate the exit velocity of gas leaving a jet engine, turbine, or rocket nozzle from the inlet conditions. Solve for any input, and get the ideal exit velocity, exit temperature, Mach number, thrust, and propulsive efficiency.
Efficiency CalculatorThermodynamicsFind efficiency, output energy, or input energy from the other two with eta = Eout / Ein. Enter any two values and the calculator solves for the third, with energy lost, input and output power, and a where-the-energy-goes chart.
Charles' Law CalculatorThermodynamicsSolve Charles' Law (V1/T1 = V2/T2) for any volume or temperature, with automatic kelvin conversion, the volume and temperature ratios, and the volume-temperature graph.
BMEP Calculator (Brake Mean Effective Pressure)ThermodynamicsWork out an engine's brake mean effective pressure from its displacement and torque, in bar and psi, or solve backwards for the torque or displacement a target BMEP would need.
Boyle's Law CalculatorThermodynamicsEnter any three of a gas's initial pressure, initial volume, final pressure, and final volume, and Boyle's Law finds the fourth, with the pressure-volume curve and unit conversion built in.
Boltzmann Factor CalculatorThermodynamicsFind the relative probability of two energy states at thermal equilibrium, or work backwards from a measured ratio to the temperature or the energy gap behind it.
Boiling Point at Altitude CalculatorThermodynamicsEnter an altitude, an air pressure, or a target boiling point and the calculator fills in the other two. Solves for water by default, or any liquid in custom mode.
Air Pressure at Altitude CalculatorThermodynamicsFind the air pressure at any altitude, or the altitude for a given pressure, with the ISA barometric formula. Also shows boiling point, effective oxygen, and a pressure-vs-altitude chart.
Air-Fuel Ratio CalculatorThermodynamicsFind the air-fuel ratio from air and fuel mass, or solve backward. Reads lambda, the equivalence ratio, and whether the mixture is rich, stoichiometric, or lean for your fuel.
Air Density CalculatorThermodynamicsCalculate air density from temperature, pressure or altitude, and humidity — plus density altitude, relative air density, partial pressures, and specific weight.
Activation Energy CalculatorThermodynamicsSolve the Arrhenius equation for activation energy, rate coefficient, frequency factor, or temperature. Enter any three values and the fourth is computed, or find the activation energy from two rate measurements.
Absolute Humidity CalculatorThermodynamicsCalculate absolute humidity from temperature and relative humidity, dew point, vapor pressure, or a measured value — plus dew point, saturation, mixing ratio, and specific humidity.Engineering
Thrust CalculatorEngineeringCalculate jet engine thrust with the general thrust equation Fn = ṁ(Ve − Vf) + (Pe − Pa)Ae, and solve for any variable. Add the pressure thrust term, the thrust-to-weight ratio, the static-versus-dynamic thrust curve, and a benchmark against real engines.
Tilt Factor CalculatorEngineeringCalculate the solar tilt factor r_b two ways, convert horizontal irradiance to the tilted plane, and see the tilt factor across the day and across tilt angles.
Sun Angle CalculatorEngineeringFind the sun's angle for any latitude, date, and time. Get the solar altitude, zenith, and azimuth, plus declination, shadow length, and a solar-panel tilt.
Solar Daylight Hours CalculatorEngineeringFind the daylight hours for any latitude and date. Enter your location and the day to get day length, solar declination, sun altitude, solar sunrise and sunset, and twilight.
Roll Rate CalculatorEngineeringCalculate the suspension roll stiffness (roll rate) of an axle from wheel rate, track width, and anti-roll bar stiffness, or solve for any one of them. Splits the spring and bar contributions, estimates body roll angle and roll gradient, and compares front-to-rear roll balance.
Rocket Equation CalculatorEngineeringSolve the Tsiolkovsky rocket equation for delta-v, exhaust velocity, or mass. Enter any three of exhaust velocity, initial mass, and final mass to find the fourth, plus mass ratio, propellant fraction, specific impulse, and mission delta-v after gravity and drag losses.
Pitching Moment CalculatorEngineeringCalculate the aircraft pitching moment from the moment coefficient, dynamic pressure, reference area, and characteristic length, or solve for any one of them. Includes a dynamic-pressure helper, a pitch-stability check, and charts.
Pipe Weight CalculatorEngineeringCalculate the weight of a pipe from its outer diameter, wall thickness or inner diameter, length and material. Reports weight per metre and per foot, the metal area, the volume, and the weight when filled with fluid.
Pipe Velocity CalculatorEngineeringCalculate the velocity of a fluid in a round pipe from the flow rate and inside diameter with v = Q/A, or solve for the diameter or flow rate instead. Reports the bore area and mass flow rate, in units from GPM to m³/s.
Movement Ratio CalculatorEngineeringCalculate suspension movement ratio, wheel rate, and ride frequency. Solve for spring travel, wheel travel, spring rate, movement ratio, or wheel rate from whatever you know.
Modern Lift Equation CalculatorEngineeringCalculate aerodynamic lift with the modern lift equation L = half rho v squared A Cl. Solve for lift, speed, wing area, air density, or lift coefficient, plus dynamic pressure, the angle-of-attack lift curve, and stall speed.
Hydraulic Ram Efficiency CalculatorEngineeringCalculate a hydraulic ram pump's D'Aubuisson and Rankine efficiency from delivered flow, waste flow, and the supply and delivery heads, with a hydraulic-power read-out and solve-for-any inputs.
Gas Pipe Sizing CalculatorEngineeringSize gas pipe diameter or find flow capacity for low- and high-pressure systems with the NFPA 54 and IFGC Mueller equations, plus standard size and BTU output.
Control Authority (Elevator Power) CalculatorEngineeringFind the change in pitching-moment coefficient from elevator effectiveness and deflection, solve for any variable, and scale it to a real pitching moment.
Bypass Ratio CalculatorEngineeringFind a jet engine's bypass ratio from the bypass and core mass flow rates, or solve for either flow. Classifies the engine and compares it with real turbofans.
Bulk Modulus CalculatorEngineeringWork out bulk modulus from a compression test, predict how far a known material compresses, convert between the five isotropic elastic constants, or derate a hydraulic fluid for working pressure, temperature and entrained air.
Buckling CalculatorEngineeringFind the critical buckling load of a column from its length, cross-section, material and end conditions, using Euler's formula for slender columns and Johnson's parabolic formula for stocky ones, with slenderness ratio, factor of safety and an eccentric-load check.
Brinell Hardness Number CalculatorEngineeringWork out the Brinell hardness number from a test force, ball diameter and indentation, or run it backwards to the force or the dent you should expect.
Breguet Range Equation CalculatorEngineeringSolve the Breguet range equation for any variable. Enter cruise speed, TSFC, lift-to-drag ratio, and weights to find an aircraft's cruise range, or leave any field blank to solve for it.
Bolt Torque CalculatorEngineeringCalculate bolt tightening torque, clamping force, and preload with the T = K d F relation. Solve for any value, pick the friction condition, and size the torque from the bolt grade.
Bolt Tensile Force CalculatorEngineeringFind the tensile force (preload) on a bolt from its tensile stress and stress area with F = sigma times A. Solve for any value, set the stress from an ISO grade and preload target, and estimate the tightening torque.
Bike Gear Ratio CalculatorEngineeringCalculate bicycle gear ratio, gear inches, development, gain ratio, and speed from your chainring, cog, and wheel, and compare every gear in your cassette.
Bernoulli Equation CalculatorEngineeringCompare pressure, speed, and height at two points along a streamline with Bernoulli's equation, solve for any unknown, and find the volumetric and mass flow rate through a pipe.
Bend Allowance CalculatorEngineeringCalculate sheet-metal bend allowance, bend deduction, setback, and flat-pattern length from bend angle, inside radius, K-factor, and thickness, or solve for the K-factor from a measured bend.
Belt Length CalculatorEngineeringFind the length of a belt around two pulleys from the pulley diameters and center distance, or solve backward for the spacing, with open and crossed belt geometry and wrap angles.
Beam Load CalculatorEngineeringCalculate the support reactions, maximum shear force, and maximum bending moment of a simply supported beam or cantilever under a point or distributed load, with shear-force and bending-moment diagrams.
Beam Deflection CalculatorEngineeringCalculate the maximum deflection, bending moment, and slope of simply supported, cantilever, and fixed beams under point or distributed loads.
Bank Angle CalculatorEngineeringFind the banking angle of a road or the bank angle of an aircraft turn from the speed and radius, or solve for the speed or radius. Includes the safe speed range with friction, load factor and rate of turn.
Average Blade Lift Coefficient CalculatorEngineeringCalculate the average blade lift coefficient of a rotor from thrust coefficient and rotor solidity using Blade Element Momentum Theory. Solve for any value, check stall margin and forward-flight limits, and read the operating regime.
Anti-Lift CalculatorEngineeringCalculate anti-lift, anti-squat, and anti-dive percentage from the side-view swing-arm angle, wheelbase, and centre of gravity height, with brake bias for the braking cases. Solve for any value.
Aerodynamic Drag CalculatorEngineeringCalculate aerodynamic drag force with the drag equation. Solve for force, speed, area, density, or drag coefficient, plus dynamic pressure, power, and terminal velocity.
3D Printing Cost CalculatorEngineeringWork out the true cost of a 3D print, including filament, electricity, machine wear, labor, and failed prints, then get a selling price from your margin and marketplace fees.Astrophysics
Planetary Surface Temperature CalculatorAstrophysicsEstimate a planet's surface temperature from its star's luminosity, orbital distance, albedo, and atmospheric optical depth, with the greenhouse effect and reverse solving for the habitable zone.
Orbital Period CalculatorAstrophysicsCalculate orbital period with Kepler's Third Law. Enter any two of the orbital radius, central mass, and period to solve for the third, with orbital and escape velocity, elliptical orbits, and altitude.
Black Hole Temperature CalculatorAstrophysicsCompute the Hawking temperature of a black hole from its mass, along with the Schwarzschild radius, entropy, luminosity, and evaporation time, or work backward from a temperature to the mass.
Black Hole CalculatorAstrophysicsCompute a black hole's Schwarzschild radius, density, surface gravity, Hawking temperature, luminosity, evaporation time, entropy, and tidal force from its mass, or solve for the mass from the event-horizon radius.
Azimuth CalculatorAstrophysicsFind the azimuth (compass bearing) and great-circle distance between two latitude-longitude points, or the altitude and azimuth of a star or the Sun from its declination and hour angle.
Antipode CalculatorAstrophysicsFind the antipode of any point on Earth. Enter a latitude and longitude to get the exact opposite coordinates, the distance through and around the planet, and the DMS format.Acoustics
Sonic Velocity CalculatorAcousticsFind the speed of sound (sonic velocity) in air, helium, hydrogen and other gases at any temperature, or work the temperature back from a measured sound speed. Adds the Mach number and flight regime, a custom gas by heat-capacity ratio and molecular weight with the choked-flow critical pressure ratio, and gas-comparison charts.
Beat Frequency CalculatorAcousticsCalculate the beat frequency of two overlapping waves from their frequencies or wavelengths, find the beat period and carrier frequency, or tune against a reference.
Air Conditioner Room Size CalculatorAcousticsEstimate the cooling capacity a room needs in BTU/hr, tons, or kW from its size, ceiling height, sun, occupants, kitchen use, climate, and insulation.