Range of Jet Calculator

How far can a commercial jet fly on a single tank? The answer comes from the Breguet range equation. Where propeller aircraft hit a wall set by available power, jets are bound by something different: how efficiently the engines convert fuel into thrust, and how cleanly the airframe slips through the air. Plug in cruise speed, engine fuel burn, lift-to-drag ratio, and how much weight the jet loses as it burns fuel, and you get a useful upper bound on horizontal range.

What is jet aircraft range?

Range is the distance an aircraft can cover between takeoff and landing while still carrying useful payload. For jets it comes down to four things: cruise speed, how much fuel the engines burn per unit of thrust, the aerodynamic lift-to-drag ratio, and how much fuel the jet carries relative to its empty weight. There's one more subtlety worth pointing out. A jet shedding fuel gets lighter as it flies, and a lighter jet needs less lift, which means less drag, which means it goes farther per kilogram of fuel than you might first guess. The Breguet equation rolls all of this into one compact expression.

A Boeing 777 or Airbus A350 can fly over 15,000 km on a single tank because two things line up: high-bypass turbofans with low TSFC, and refined wings hitting L/D ratios around 19 to 21. Fighter jets sit at the other end. Their swept wings are tuned for supersonic flight, so cruise L/D can drop into the 4 to 8 range.

How to use this calculator

Fill in the five inputs: cruise true airspeed, thrust-specific fuel consumption (TSFC), lift-to-drag ratio (L/D), and the initial and final weights. The range falls out. To work it the other way, enter range plus any four of the others, and the missing variable is solved for you. That's the part flight planners actually use: "what speed do I need to hit?" or "how much fuel should I load?"

Units are flexible. Switch between metric (m/s, kg) and imperial (knots, lb) with the unit toggles on each field.

Understanding the Breguet range equation

The Breguet range equation for jet aircraft is written as:

R = \frac{v}{\text{TSFC}} \cdot \frac{L}{D} \cdot \ln\!\left(\frac{W_i}{W_f}\right)

Each term has a physical meaning. The $v/\text{TSFC}$ ratio is velocity per unit of fuel burned, i.e., the distance covered per kilogram of fuel each newton of thrust consumes. The $L/D$ term is aerodynamic efficiency: at L/D of 18, the wing produces 18 units of lift for every unit of drag. The logarithmic piece $\ln(W_i/W_f)$ , called the fuel fraction, accounts for the jet becoming lighter and more efficient as fuel burns off.

A worked example. Take a commercial jet at v = 250 m/s, TSFC = 0.00002 kg/(N·s), L/D = 18, takeoff weight 200,000 kg, landing weight 150,000 kg. Compute the weight-ratio log first: $\ln\left(\frac{200{,}000}{150{,}000}\right) = \ln(1.333) \approx 0.287$ . Then

\text{range} = \left(\frac{250}{0.00002}\right) \times 18 \times 0.287 = 12{,}500{,}000 \times 18 \times 0.287 \approx 64{,}738{,}000 \text{ m}

or about 64,738 km. Real-world range comes out lower than that. Subtract climb, descent, reserves, and headwinds. Breguet is the upper bound.

Real-world applications

Aircraft designers reach for Breguet during preliminary sizing to size fuel volume and wing area against a target mission. Airline planners use it to check fuel reserves and decide whether a given city pair flies non-stop or needs a tech stop. Pilots see the same physics behind Maximum Range Cruise (MRC) profiles, which trade airspeed against L/D to maximize the product $v \cdot (L/D)$ .

Engineering students often use Breguet to compare engine generations. A 1960s turbojet sat around $\text{TSFC} \approx 0.000028 \text{ kg/(N}\cdot\text{s)}$ ; a modern high-bypass turbofan sits closer to 0.000015. On the same airframe, that gap alone nearly doubles the achievable range.

Tips for maximizing range

A few strategies do most of the work. Climb as you burn fuel: cruise-climb profiles step the jet up into thinner air as it gets lighter, which cuts drag. Fly at the speed that maximizes $v \times (L/D)$ ; push too fast and drag spikes, too slow and the wing climbs to a higher angle of attack, which also spikes drag. On the design side, choose high aspect-ratio wings for the L/D you can get, and pair them with the lowest-TSFC engines you can afford. Those two compound.

Frequently asked questions

Does the Breguet equation account for climb, descent, and reserves?

Not at all. The equation assumes pure cruise from start to finish, so real mission range usually lands at 80 to 90% of the Breguet number once you subtract climb fuel, descent allowances, and FAA-mandated reserves.

Why is the weight term logarithmic instead of linear?

Because the jet has to carry its own fuel to burn it. As fuel burns off, the jet gets lighter and needs less thrust, so every kilogram in the tank does more work the closer you are to the destination. Integrate that effect over the trip and you get a natural log.

What is a typical L/D ratio for commercial jets?

Modern airliners cruise at L/D somewhere between 16 and 21. Gliders can clear 60. Fighter jets in supersonic cruise can drop below 5.

Why are headwinds and tailwinds not included?

Breguet gives range through the airmass, i.e., still-air range. To get ground range, add or subtract the wind component times flight time. Most flight planners apply that wind correction as a separate step.

How does this compare to the propeller (Breguet) range equation?

Propeller aircraft use a slightly different form: $R = \left(\frac{\eta}{c}\right) \times \left(\frac{L}{D}\right) \times \ln\left(\frac{W_i}{W_f}\right)$ , where η is propeller efficiency and c is brake specific fuel consumption. For jets, $v/\text{TSFC}$ replaces $\eta/c$ .