Wing Loading Calculator

Wing loading is the weight an aircraft carries per unit of wing area, and it shapes how a plane flies more than almost any other single number. It sets how fast a plane has to move to stay in the air and how tightly it can turn. The figure matters whether you're sketching a model glider, tuning a trainer, or sizing up fighter jets on paper. Enter weight and wing area below to get the loading, or enter any two of the three values to solve for the third.

What is wing loading?

Picture the average load each square meter of wing has to carry. A plane with a heavy body and stubby wings runs a high wing loading, so it has to move fast to make enough lift. Give that same plane big wings and the loading drops, letting it fly slowly and still hold altitude.

The trade-offs run in opposite directions. A high loading raises the stall speed and stretches out the takeoff roll, but it also smooths out the ride in turbulence, which is part of why airliners feel so steady in rough air. A low loading buys tighter turns, shorter takeoffs, and gentler slow-speed handling, at the cost of getting tossed around when the air turns bumpy. Gliders live near the bottom of the scale, around 20 to 40 $\text{kg}/\text{m}^2$ , while a Boeing 747 tops 700 $\text{kg}/\text{m}^2$ .

How to use this calculator

Fill in any two of the three fields, weight, wing area, or wing loading, and the third one fills itself in. Use the dropdown next to each field to switch between metric and imperial units. Which value gets solved depends on which two you enter.

Say your aircraft weighs 1,100 kg and has $16.2 \text{ m}^2$ of wing area. Enter both and you get the wing loading. Start instead with a target loading and a known weight, and you get the wing area you'd need to hit it.

Understanding the wing loading formula

Wing loading is weight divided by wing area:

WL = \frac{W}{S}

Where $WL$ is wing loading ( $\text{kg}/\text{m}^2$ ), $W$ is the total weight of the aircraft (kg), and $S$ is the wing reference area ( $\text{m}^2$ ). You can rearrange this to solve for weight or area:

W = WL \times S \qquad S = \frac{W}{WL}

Example: Cessna 172 Skyhawk - a common training aircraft weighing 1,100 kg with 16.2 $\text{m}^2$ of wing area:

WL = \frac{1{,}100}{16.2} \approx 67.9 \text{ kg/m}^2

That low loading is why the Cessna can fly at just 87 km/h and land on short runways, exactly what you want in a trainer.

Example: F-16 Fighting Falcon - at a typical combat weight of 12,000 kg with 28 $\text{m}^2$ of wing area:

WL = \frac{12{,}000}{28} \approx 428.6 \text{ kg/m}^2

Over six times the Cessna's loading. The F-16 is rock-solid at supersonic speeds but needs a minimum landing speed around 260 km/h.

Applications of wing loading

Wing loading plays a role across many areas of aviation and engineering:

Designers pick a target wing loading early on and size the wings around it to hit a required range, cruise speed, or takeoff distance.
Pilots and engineers compare loadings across aircraft to get a quick read on how a plane will handle and where its limits sit.
In RC and drone building, the figure (usually in $\text{g}/\text{dm}^2$ ) predicts how a model will fly before it leaves the workbench; trainers usually aim for 20 to 40 $\text{g}/\text{dm}^2$ .
Sailplane designers keep wing loading low to stretch out glide performance and hold down the sink rate.

Tips for working with wing loading

Wing loading drops over a flight as fuel burns off, so a fully fueled aircraft sits higher than the same plane near the end of its trip.
When comparing aircraft, use the same weight standard (empty weight, maximum takeoff weight, or typical operating weight).
Wing loading alone does not tell the whole story. Wing shape, airfoil selection, aspect ratio, and thrust-to-weight ratio all affect flight performance.
As a rough guide: below 50 $\text{kg}/\text{m}^2$ is very light loading, 50-200 $\text{kg}/\text{m}^2$ is moderate, and above 300 $\text{kg}/\text{m}^2$ is heavy.

Frequently asked questions

What is the difference between kg/m² and N/m² for wing loading?

The $\text{kg}/\text{m}^2$ version uses mass, while $\text{N}/\text{m}^2$ treats weight as a force. To convert, multiply $\text{kg}/\text{m}^2$ by 9.81 (gravitational acceleration). Most aviation references use $\text{kg}/\text{m}^2$ or $\text{lb}/\text{ft}^2$ for convenience, while formal engineering calculations use $\text{N}/\text{m}^2$ (pascals).

Does wing loading change during flight?

It does. As fuel burns off, the aircraft gets lighter and its wing loading drops, which lowers the stall speed and sharpens handling toward the end of a flight. A long-range jet can shed thousands of kilograms of fuel, enough to shift its loading noticeably.

What wing loading should I target for an RC model?

For slow-flying trainers, aim for 20-40 $\text{g}/\text{dm}^2$ (2-4 $\text{kg}/\text{m}^2$ ). Sport aerobatic models work well at 50-80 $\text{g}/\text{dm}^2$ . Scale models and RC jets typically go higher, but handling becomes less forgiving as wing loading increases.

Can two aircraft with the same wing loading fly very differently?

Easily. Wing loading is only one piece of the picture. Aspect ratio, airfoil shape, sweep angle, and thrust-to-weight ratio all feed into how a plane handles, so two aircraft with the same loading but different wing geometry can fly nothing alike.