Advanced Mean Aerodynamic Chord Calculator

Calculator Inputs

Use the responsive input grid below. Large screens show three columns, smaller screens show two, and mobile shows one.

Wing Type

Unit System

Leading Edge Sweep (deg)

Root Chord

Tip Chord

Total Wingspan

Reference Datum X Offset

Plotly Geometry Graph

The graph displays the wing planform outline and the MAC position. It updates after each calculation.

Example Data Table

Case	Root Chord (m)	Tip Chord (m)	Span (m)	Sweep (deg)	MAC (m)	Y of MAC (m)	Area (m²)
Regional UAV	5.00	2.00	18.00	12.00	3.7143	3.8571	63.0000
Rectangular Trainer	3.20	3.20	14.00	0.00	3.2000	3.5000	44.8000
Fast Test Platform	6.00	1.80	24.00	18.00	4.2769	4.9231	93.6000

These sample rows help verify the calculator before applying project-specific geometry.

Formula Used

1) Taper Ratio
λ = C_t / C_r

2) Wing Area
S = b × (C_r + C_t) / 2

3) Mean Aerodynamic Chord
MAC = (2 / 3) × C_r × (1 + λ + λ²) / (1 + λ)

4) Spanwise Location of MAC
y_MAC = (b / 6) × (1 + 2λ) / (1 + λ)

5) Longitudinal MAC Leading Edge
x_LE,MAC = y_MAC × tan(Λ_LE)

6) Quarter-Chord Position of MAC
x_c/4,MAC = x_LE,MAC + 0.25 × MAC

These equations are best suited to straight tapered or rectangular wings with a single panel per side. Cranked, delta, curved, or multi-panel wings should be evaluated section by section.

How to Use This Calculator

Select the wing type and the preferred unit system.
Enter root chord, tip chord, total wingspan, and leading-edge sweep.
Enter the datum offset only if you want quarter-chord locations from a custom reference.
Press the calculate button to show results above the form.
Review MAC, wing area, taper ratio, spanwise MAC station, and quarter-chord location.
Use the CSV or PDF buttons to export the calculation summary.
Inspect the Plotly graph to confirm geometry and MAC placement visually.
Compare your numbers with the example table if you want a fast sanity check.

Frequently Asked Questions

1) What is mean aerodynamic chord?

Mean aerodynamic chord is the representative wing chord used for aerodynamic and stability analysis. It matches the pitching and lift behavior of the actual tapered wing more closely than a simple average chord.

2) Is MAC the same as mean geometric chord?

No. Mean geometric chord is simply wing area divided by span. MAC weights the chord distribution aerodynamically, so the two values only match for special cases like a rectangular wing.

3) Can this calculator handle a rectangular wing?

Yes. Choose the rectangular option and the tool automatically sets tip chord equal to root chord. In that case, the MAC equals the constant wing chord.

4) Why is sweep included in the calculation?

Sweep affects the longitudinal position of the MAC. A larger leading-edge sweep moves the MAC leading edge and quarter-chord point farther aft relative to the root leading edge.

5) Which wings are not covered well by this method?

Highly curved, cranked, compound-taper, delta, and multi-panel wings need segmented analysis. This page is intended for straight rectangular or single-taper planforms with a clear leading-edge sweep value.

6) What does the datum offset input do?

The datum offset shifts the reported quarter-chord location to your chosen aircraft reference. Use zero if you only want positions measured from the root leading edge.

7) Why does spanwise MAC location matter?

It tells you where the representative chord sits across the wing. Designers use it when locating aerodynamic centers, plotting reference geometry, and checking stability and balance assumptions.

8) Should I use metric or imperial units?

Either works. The calculator keeps results in the same unit family you selected. Just enter all length inputs consistently to avoid scaling mistakes in area and position outputs.