RC Airplane Wing Loading Calculator

Under about 8 oz/sq ft is typically considered park-flyer territory — light, slow, and forgiving. Loadings above roughly 26-28 oz/sq ft push into pattern or racer territory, where the plane flies fast but needs more runway and more pilot skill to land safely. Most general-purpose sport planes fall somewhere in the middle of that range.

Different airfoil shapes generate different maximum lift coefficients at low speed. A flat-bottom or under-cambered airfoil, common on trainers and slow flyers, keeps producing useful lift at a lower airspeed than a symmetrical aerobatic airfoil, so this calculator applies a multiplier to the base stall-speed estimate depending on which profile you select.

No — treat it as an early planning estimate, not something to build a maiden-flight checklist around. The formula uses a simplified square-root relationship to wing loading and does not account for propeller wash, Reynolds number at your specific scale, or your airframe's actual measured lift coefficient — all of which shift real stall speed in ways a quick calculator can't.

For a fixed wing area, yes — more weight raises wing loading, and this calculator's maneuverability rating drops as wing loading climbs. If you also increase wing area to compensate, wing loading (and therefore the maneuverability estimate) can stay flat or even improve despite the added weight, since wing loading is just weight divided by wing area and responds equally to a proportional change in either one.

Stall speed is the estimated minimum airspeed before the wing stops producing enough lift to fly. Cruise speed is calculated as 1.5 times that stall speed, a common rule-of-thumb margin RC pilots use for comfortable, controllable flight rather than flying right at the ragged edge of a stall.