Wing Loading Calculator
Enter your aircraft weight and wing area to get wing loading (WL), wing cube loading (WCL), estimated stall speed, and minimum level-flight turn radius. Switch between metric and imperial, pick a preset aircraft, or enter your own values. Results update as you type. The WCL category panel tells RC and model-aircraft builders how their design will handle.
What is wing loading?
Wing loading (WL) is the ratio of an aircraft's weight to its total wing area. It is calculated by dividing the gross weight (in kg or lb) by the projected planform area of all lifting surfaces combined (in m² or ft²). The result, expressed in kg/m² or lb/ft², is one of the most important single numbers in aerodynamics: it directly determines how fast the wing must move through the air to generate enough lift to sustain flight. A low wing loading means the wing can stay airborne at a slow speed; a high wing loading means the aircraft needs to fly fast to stay up. Gliders, which must fly slowly to exploit thermals, have wing loadings well below 60 kg/m². Fighter jets, which trade slow-speed maneuverability for high-speed performance and gust penetration, may exceed 500 kg/m².
Wing cube loading and RC aircraft handling
Wing loading on its own is an incomplete guide to how an aircraft handles, because aerodynamics does not scale linearly with size. A small model that looks like a scaled-down airliner will not fly like one. Wing cube loading (WCL) corrects for this by dividing weight by wing area raised to the power 1.5 (S^1.5). The result, measured in oz/ft^1.5 in the RC community or kg/m^1.5 in SI units, stays comparable across aircraft of very different sizes. A WCL below about 5 oz/ft^1.5 produces a floater or trainer with very slow, gentle handling. Values between 5 and 9 characterise relaxed-sport and sport aircraft. Above 13 oz/ft^1.5 the model is in the pylon-racer territory, demanding experienced hands. Full-scale aircraft typically fall between 5 and 15 oz/ft^1.5 on this scale, sitting in the sport to moderate-performance band.
Stall speed and turn performance
Stall speed is the minimum airspeed at which the wing generates enough lift to support the aircraft. It rises with the square root of wing loading: double the wing loading and the stall speed increases by about 41 percent. At sea-level International Standard Atmosphere conditions the formula is V_stall = sqrt(2 * WL / (rho * C_L,max)), where WL is the wing loading in Pa (N/m²), rho is air density (1.225 kg/m³ at sea level) and C_L,max is the maximum lift coefficient. Minimum turn radius in level flight is governed by the stall speed and bank angle: R = V² / (g * tan(bank)). The associated load factor is n = 1 / cos(bank angle), so a 60 deg bank imposes 2 g. Higher wing loading therefore means faster stall, faster minimum turn radius at the cost of a larger physical turn circle, and higher approach and landing speeds.
How to reduce wing loading
Because wing loading equals weight divided by area, you can lower it by reducing weight or enlarging the wing. For full-scale aircraft this means removing payload or fuel, or fitting larger or extended wing-tips. High-lift devices (flaps, slats) effectively increase the wing's maximum lift coefficient rather than the physical area, which reduces the stall speed without changing the wing loading number itself. For RC model builders the most practical lever is wing area: a slightly longer, broader wing can dramatically change the handling category. For very light aircraft and drones operating at altitude, the reduced air density raises the effective stall speed, so designers must allow extra margin compared to sea-level calculations.
Wing loading by aircraft type (approximate)
| Aircraft type | Wing loading (kg/m²) | Stall character |
|---|---|---|
| Hang glider / Paraglider | 5-15 | Very slow, floats easily |
| RC trainer / Park flyer | 10-30 | Docile, easy to fly |
| Sailplane / Glider | 30-60 | Slow stall, efficient glide |
| Ultralight / Microlight | 20-35 | Slow landing, gentle handling |
| Cessna 172 Skyhawk | 68 | Slow, forgiving |
| Piper Cherokee PA-28 | 73 | Stable, predictable |
| Boeing 737-800 | 455 | High approach speed |
| Boeing 747-400 | 740 | Very high approach speed |
| Airbus A380 | 663 | Very high approach speed |
| F-16 Fighting Falcon | 431 | Demanding approach |
| F-22 Raptor | 377 | High-energy approach |
| MiG-21 Fishbed | 452 | Hot, fast approach |
Typical maximum take-off weight divided by wing area. Values are representative; actual numbers vary by variant and configuration.
Frequently asked questions
What is wing loading and why does it matter?
Wing loading is the aircraft's gross weight divided by its total wing area. It determines the minimum airspeed needed to generate lift, so a higher wing loading means a faster stall speed, a faster landing, and less sensitivity to turbulence gusts. A lower wing loading means slower, more docile handling, slower stall, and better thermal soaring performance.
What is wing cube loading and why do RC flyers use it?
Wing cube loading (WCL) divides weight by wing area raised to the power 1.5. Unlike basic wing loading, WCL remains comparable across aircraft of different sizes because aerodynamic forces scale with area while inertia scales with volume. RC pilots and model builders use it to predict how a model will handle: below 5 oz/ft^1.5 is trainer-docile, above 13 oz/ft^1.5 approaches pylon-racer twitchiness.
How does wing loading affect stall speed?
Stall speed scales with the square root of wing loading. If you double the wing loading, the stall speed increases by about 41 percent. This is why heavily loaded aircraft (fighters, airliners) need long runways and land at high speed, while gliders and ultralights can fly very slowly.
What is a good wing loading for a Cessna 172?
The Cessna 172 Skyhawk has a maximum take-off weight of about 1,111 kg and a wing area of 16.17 m², giving a wing loading of roughly 68 kg/m² (about 14 lb/ft²). This is on the low end for powered aircraft, which is why the 172 is so forgiving and used widely for primary training.
Why do fighter jets have high wing loading?
Fighters are designed to fly fast, penetrate turbulence without pitching up, and carry heavy fuel and weapons loads. High wing loading makes them less sensitive to gusts (smoother ride at low altitude and high speed) and allows a smaller, lighter wing. The trade-off is a fast stall and landing speed, which demands long runways and careful pilot technique.
How do flaps change wing loading?
Extending flaps does not change the wing loading figure (which depends on physical area), but it increases the maximum lift coefficient (C_L,max). A higher C_L,max lowers the stall speed for the same wing loading. Modern airliners use elaborate multi-element flaps to more than double C_L,max, allowing enormous planes with high wing loadings to land at acceptably slow speeds.