Wing Area Calculator
Wing area is the planform area of a wing, the outline you see looking straight down at it. It drives lift, stall speed, and wing loading, so getting it right matters whether you are sizing an RC trainer or checking a full scale design. This calculator handles six wing shapes and reports not just the area but the aspect ratio, mean aerodynamic chord, and taper ratio that designers actually use, plus wing loading and an estimated stall speed when you enter a weight.
Performance extras (optional)
Results stay hidden until you click Calculate. The sweep angle input is recorded but never changes an output, and switching units relabels inputs without converting numbers.
Quick Answer
Wing area is span times the average chord for the shape you pick, and aspect ratio is span squared divided by that area. For the worked example, a trapezoidal wing with a 36 ft span, 5.2 ft root chord, and 3.9 ft tip chord gives 163.80 sq ft of area, an aspect ratio of 7.9121, a mean aerodynamic chord of 4.5810 ft, and a taper ratio of 0.7500. On a 2,550 lb airplane with CLmax 1.5 that is 15.57 lb per sq ft of wing loading and an estimated stall speed of 63.7 mph.
How to use the wing area calculator
Pick the unit system first, then the shape, then the dimensions. Order matters because the unit toggle does not convert numbers: set imperial or metric before you type anything.
- Choose units. Imperial means feet, pounds, and mph; metric means meters, kilograms, and km/h. Switching later only changes the labels, so re-enter your numbers if you switch.
- Choose the planform. Rectangular, trapezoidal, triangular, elliptical, swept, or delta. Only the chosen shape inputs show, so a hidden shape cannot pollute the result.
- Enter the dimensions. Every dimension must be greater than zero or the tool stops with a plain message naming the missing value.
- Add performance extras if you want them. Aircraft weight adds wing loading and stall speed; CLmax defaults to 1.5 when left blank and must be greater than zero when entered.
Two inputs that look live but are not. The sweep angle on the swept wing shape is never read by the calculation, so changing it changes nothing. It is kept because the live tool had it and removing a field silently would be worse than labeling it honestly. The same applies in reverse to units: the toggle relabels but never converts, so 36 typed as feet stays 36 when the label switches to meters.
Wing area formulas for all six shapes
Every shape starts from the same idea: area is span times the average chord, and aspect ratio is span squared divided by area. The shapes differ only in what the average chord is.
| Shape | Area (S) | MAC | Taper ratio |
|---|---|---|---|
| Rectangular | S = span x chord | Chord | 1 |
| Trapezoidal (tapered) | S = (span / 2) x (root + tip) | (2 / 3) x root x ((1 + taper + taper squared) / (1 + taper)) | Tip / root |
| Triangular | S = (span x root) / 2 | (2 / 3) x root | 0 |
| Elliptical | S = (pi / 4) x span x max chord | (8 / (3 x pi)) x max chord, about 84.9 percent of max chord | 0 |
| Swept | S = (span / 2) x (root + tip) | Same tapered formula as trapezoidal | Tip / root |
| Delta | S = (span x root) / 2 | (2 / 3) x root | 0 |
Aspect ratio is span squared divided by area for every shape except the rectangular case, where the tool uses span divided by chord, which is algebraically the same thing. Taper ratio is tip chord divided by root chord, with triangular, elliptical, and delta wings reported as 0 because their tip chord is zero in this model.
The elliptical MAC correction. The previous version of this tool reported the elliptical MAC as the maximum chord itself. That is wrong under the integral definition of MAC, which weights chord by chord squared along the span. Integrating the elliptical chord distribution gives 8 divided by 3 pi times the maximum chord, about 84.9 percent, which matches the 85 percent figure in the model aircraft MAC references. This draft fixes that one output: for a 40 ft span with a 4 ft maximum chord, MAC is now 3.3953 ft instead of 4.0000 ft. Area, aspect ratio, and taper ratio for the elliptical shape are unchanged, and no other shape is affected.
Worked example: a Cessna 172 class trainer
Take a trapezoidal wing with a 36 ft span, a 5.2 ft root chord, and a 3.9 ft tip chord, on a 2,550 lb airplane with CLmax 1.5. Select Trapezoidal (tapered) wing, enter the numbers, and the calculator returns:
| Output | Value |
|---|---|
| Wing area (S) | 163.80 sq ft |
| Aspect ratio | 7.9121 |
| Mean aerodynamic chord | 4.5810 ft |
| Taper ratio | 0.7500 |
| Wing loading | 15.57 lb per sq ft |
| Estimated stall speed | 63.7 mph |
The real Cessna 172 publishes about 174 sq ft of wing area and an aspect ratio near 7.4, so this simplified trapezoid lands in the right neighborhood; the small difference is the real wing more complex planform. The wing loading near 15.6 lb per sq ft is typical for a four seat trainer, and the stall speed estimate sits close to the published range once you allow for the actual CLmax with flaps. The prefilled inputs match this example, so clicking Calculate reproduces every figure above.
Wing loading and estimated stall speed
Wing loading is weight divided by wing area, and it is the number that connects geometry to behavior. Lower loading means a lower stall speed, which is why the calculator pairs the two.
The stall speed estimate comes from setting lift equal to weight in the lift equation: V = square root of (2W / (density x S x CLmax)). It uses sea level air density, 0.002377 slugs per cubic foot imperial or 1.225 kg per cubic meter metric, and your CLmax, so it answers roughly how slow this wing can fly for comparing designs, not for flight planning. That estimate is a 1 g, level flight, sea level figure: turning flight, altitude, flaps, contamination, and center of gravity all move the real stall speed, sometimes a lot.
Once you have these numbers, a glide distance calculator shows how far that same wing carries you with the engine out, and a takeoff distance calculator estimates the runway the design needs. For trip planning, the flight length calculator covers time and distance, and the lift rate calculator works the lift side of the same equations. If you need volume rather than area, the wing volume calculator starts from area and adds thickness.
What competing wing area calculators miss
Most wing area tools we reviewed cover three or four planforms at most, usually rectangular, tapered, and elliptical. Triangular and delta wings are missing nearly everywhere, even though delta planforms show up in RC models and supersonic designs. Several tools report only the area, leaving you to compute aspect ratio and MAC by hand, and the ones that do show MAC rarely explain what to do with it.
- Three shape tools (DomyCalculations): rectangular, trapezoidal, and elliptical only, with a worked rectangular example. No triangular, swept, or delta shape, and no performance outputs.
- Formula pages with a tool (CalculatorsHub): good formula list including the tapered MAC formula, plus wing loading, but the sweep angle is presented as a computed output from a sweep offset input, which confuses a recorded angle with a derived one. No stall speed, and no delta or triangular shape in its formula set.
- Model aircraft references (Airfield Models): excellent MAC material, including the 85 percent elliptical figure this draft now uses, but they are references, not calculators: you do the arithmetic by hand.
- General formula roundups: area formulas with a correction factor between 0.85 and 1.0 for non rectangular features. A fudge factor is not a planform, and it cannot reproduce a tapered or elliptical area exactly.
- The gap this page fills: six planforms, aspect ratio, MAC, and taper ratio on every calculation, optional wing loading with a stall speed estimate, and a unit toggle that keeps feet and meters straight, with the two honest limits (dead sweep angle, no unit conversion) stated in the tool itself.
This calculator is for education and preliminary design only. It uses simplified planform geometry and sea level air density, and it does not account for winglets, flaps, twist, or airfoil specifics. Verify real designs against manufacturer data and qualified aerospace engineering analysis before building or flying anything.
Frequently asked questions
Wing area, also called planform area and written S, is the area of the wing outline seen from directly above, in square feet or square meters. It is the reference area used in the lift and drag equations, which is why nearly every performance calculation starts here.
Multiply wingspan by chord: S = span x chord. A 20 ft span with a 5 ft chord gives 100 sq ft. It is the simplest case because the chord is constant from root to tip.
The MAC is the chord of an equivalent rectangular wing with the same area and aerodynamic behavior. Designers use it to locate the center of gravity, usually expressed as a percentage of MAC, so a wrong MAC means a wrong balance point. For an elliptical wing the MAC is 8 divided by 3 times pi, about 84.9 percent, of the maximum chord, not the maximum chord itself.
Taper ratio is tip chord divided by root chord. A ratio of 1 means a rectangular wing; 0 means the wing tapers to a point. Lower taper ratios reduce tip weight and induced drag but make the wing more prone to tip stall.
It depends on the mission. Trainers run about 4 to 6, general aviation 6 to 8, and high performance sailplanes 12 to 20 or more. Higher aspect ratio means less induced drag and better glide, at the cost of a longer, heavier, structurally demanding wing.
Yes, for area, aspect ratio, MAC, and taper ratio, which are scale independent as long as every input uses the same unit. For wing loading and stall speed, use feet with pounds or meters with kilograms, because those two outputs use sea level air density in those unit systems. Inches or centimeters will give the right area but the wrong stall speed.
No. Sweep angle does not change the planform area; a swept wing with the same span and chords has the same top down area as an unswept tapered wing. Sweep affects where the MAC sits, pitch behavior, and high speed drag, which is why the tool keeps the angle as a recorded input rather than folding it into the area. Note that the angle you enter does not change any output number.
No. The unit toggle only relabels the inputs. If you enter 36 ft and then switch to metric, the tool still treats the number as 36, now in meters. Enter your dimensions fresh in the unit system you select, and select the system before you type.
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References
- National Aeronautics and Space Administration, Glenn Research Center. The Lift Equation (lift equals lift coefficient times density times half velocity squared times wing area). Accessed October 24, 2026.
- Embry-Riddle Aeronautical University, Introduction to Aerospace Flight Vehicles. Wing Shapes and Nomenclature (aspect ratio definition, elliptical planform area, and planform geometry). Accessed October 24, 2026.
- Airfield Models. How to Find or Calculate the Mean Aerodynamic Chord (MAC) of a Wing (elliptical wing MAC at 85 percent of root chord and the tapered wing MAC formula). Accessed October 24, 2026.
- Aircraft Owners and Pilots Association. Aerodynamics: Nothing but a number (what published stall speeds assume and what moves them). Accessed October 24, 2026.
- National Aeronautics and Space Administration, Glenn Research Center. Interactive Performance Prediction (sea level air density near 0.00237 slugs per cubic foot). Accessed October 24, 2026.
- Airfield Models. How to Calculate the Wing Area for Constant Chord, Tapered and Delta Wings (rectangular, tapered, and delta wing area formulas and the note that sweep does not change the tapered area). Accessed October 24, 2026.