Formula Used
Wing Loading: Wing loading = all-up weight / wing area.
Trapezoid Area: Area = span × (root chord + tip chord) / 2 × lifting surfaces.
Cubic Wing Loading: Cubic loading = weight in ounces / area in square feet1.5.
Aspect Ratio: Aspect ratio = span squared / wing area.
Stall Speed: Stall speed = √(2 × weight force / air density × area × CLmax).
Target Weight: Target weight = target loading × wing area.
How to Use This Calculator
Choose direct area if your plan already lists total wing area. Choose trapezoid mode if you know span, root chord, and tip chord.
Enter the final flying weight. Include battery, receiver, servos, glue, covering, paint, and landing gear.
Use one lifting surface for a normal monoplane. Use two for a biplane when both wings produce useful lift.
Keep air density at 1.225 for standard sea level checks. Change it for high altitude or special testing.
Press Calculate. The result appears above the form. Use CSV or PDF buttons to save the output.
Wing Loading Basics
Wing loading compares aircraft weight with lifting area. It is a key design value for radio control models. A low value usually means gentle handling. A high value often means higher speed, longer turns, and faster landings. The calculator converts all entries to consistent units. It then reports loading in common model aircraft formats.
Why It Matters
Construction choices change wing loading fast. A thicker spar, larger battery, heavy covering, or dense repair can raise all-up weight. A small wing must carry that weight with less area. The model then needs more lift per square foot. That can increase stall speed. It can also make takeoff distance longer. Builders can use the result before cutting parts. Pilots can use it after repairs or battery changes.
Advanced Design Checks
The direct area mode works when the plan shows total wing area. The trapezoid mode helps when only span and chords are known. It estimates area from root chord, tip chord, and panel span. The tool also finds aspect ratio and mean aerodynamic chord. These values help compare trainers, gliders, sport models, and scale aircraft. Cubic wing loading adds another useful view. It reduces size bias. A small park flyer and a larger model can be compared more fairly.
Stall Speed Insight
The stall estimate uses weight force, air density, wing area, and maximum lift coefficient. It is not a wind tunnel result. It is a planning estimate. Airfoil shape, surface finish, flaps, washout, prop wash, and pilot technique can change the real value. Still, the number is useful. It warns when a design may need more speed.
Better Building Decisions
Use conservative data for early planning. Enter final battery weight if known. Include servos, receiver, landing gear, paint, glue, and fasteners. Check several target weights. If loading is high, reduce weight or increase area. You can also choose a stronger airfoil, add flaps, or select a larger wing. Export the results for build notes. Share the CSV with a club member. Save the PDF with your design sheet. Good records make future changes easier and safer.
Recheck after maiden flights, because trim changes and hardware swaps often alter weight, balance, and safe landing behavior during later sessions too.
FAQs
What is RC wing loading?
It is the flying weight divided by wing area. Most builders read it as ounces per square foot. It shows how much load each wing area must carry.
Should I use empty weight or flying weight?
Use flying weight. Include battery, fuel if used, propeller, receiver, servos, landing gear, paint, covering, and repairs. The wing carries everything during flight.
What is cubic wing loading?
Cubic wing loading compares models of different sizes more fairly. It divides weight by wing area raised to 1.5. Many designers use it for handling estimates.
Does low wing loading always fly better?
No. Low loading helps slow flight. Yet the model also needs enough structure, power, stiffness, and wind penetration. Very low loading can feel floaty.
Why does stall speed change?
Stall speed changes with weight, area, air density, and maximum lift coefficient. Flaps, airfoil shape, surface finish, and washout also affect real stall behavior.
Can I use this for biplanes?
Yes. Enter two lifting surfaces if both wings are similar and useful. For unusual layouts, calculate total effective lifting area before using direct area mode.
What target loading should I enter?
Use a value that matches your model type. Trainers often use lighter targets. Sport and scale models can use higher targets, depending on speed and skill.
Is the stall speed exact?
No. It is an estimate for planning. Real stall speed depends on build quality, airfoil data, turbulence, prop wash, control setup, and pilot technique.