RC Airplane CG Calculator

Estimate RC airplane center of gravity, neutral point and mean aerodynamic chord. Explore conventional, flying-wing and delta layouts.

Fixed-wing powertrain →

Check the example values.

01Configuration

Aircraft nameLength unitWing layoutTail layout

Units convert automatically.

02Main wing

13 example values

Root chordcmExample

#	Tip chord cm	LE offset cm	Panel half-span cm
1	Example to check	Example to check	Example to check
2	Example to check	Example to check	Example to check
3	Example to check	Example to check	Example to check
4	Example to check	Example to check	Example to check

Up to five panels per side. Measure offset from the root leading edge.

03Horizontal tail

14 example values

Root chordcmExample

#	Tip chord cm	LE offset cm	Panel half-span cm
1	Example to check	Example to check	Example to check
2	Example to check	Example to check	Example to check
3	Example to check	Example to check	Example to check
4	Example to check	Example to check	Example to check

Up to five panels per side. Measure offset from the root leading edge.

Tail positioncmExample

From the main wing root. Enter a negative value for a forward canard.

04Stability & fuselage

3 example values

Aft static margin%ExampleAerodynamic centre / MAC%ExampleTail effectiveness0–1Example

Static margin · 12.5% forward · 7.5% aft

Aft margin presetTail preset

Stability settings

Static margin moves the aft CG limit ahead of the neutral point. The forward limit is another 5% of reference MAC ahead.

Fuselage correction · Off

Use a verified model type. Enable only if you know your aircraft’s model ID.

I know my aircraft’s model ID.Fuselage correction

30 example values to check

cm · 1 wing · Aft margin 7.5%

How to calculate a suggested aircraft CG range

Choose the aircraft layout, enter wing-panel dimensions and add tail or canard geometry where applicable. Set the stability parameters and check the planform preview before interpreting the suggested CG range. Read the neutral point and mean aerodynamic chord (MAC) alongside the range, keeping the displayed units and reference positions consistent.

Flying-wing and delta-wing CG calculations

For a flying wing or delta wing, use the appropriate tailless layout and describe the planform with wing panels. Check the root and tip chords, sweep and half-span inputs against the preview. This estimates geometry-based CG guidance; it does not perform a complete delta-wing aerodynamic design.

Suggested CG versus actual aircraft balance

This tool does not calculate the actual loaded CG from component masses and positions. Battery placement and other equipment still determine the assembled aircraft's balance. Check the actual CG separately and compare the estimate with the aircraft manufacturer's guidance.

Frequently asked questions

How do I enter a flying wing or delta wing?

Select the appropriate tailless layout and describe the wing using panel root chords, tip chords, sweep and half-spans. Compare the planform preview with your aircraft before calculating; this provides CG guidance rather than a complete delta-wing design analysis.

What do MAC and neutral point mean in the results?

Mean aerodynamic chord (MAC) is the reference chord used to express relative positions such as a CG percentage. The neutral point is a stability reference from the geometry model; the suggested CG range also depends on the chosen stability settings, so these results are not interchangeable.

Will moving the battery change the calculated CG range?

Moving the battery changes the assembled aircraft’s actual balance, but this calculator does not use component masses or positions. Measure the actual loaded CG separately and compare it with the suggested range and the aircraft manufacturer’s guidance.