This Aircraft Calculator is used to calculate the
Center of gravity and balance of your aircraft. I hope this is helpful.
25% - 30% MAC is generally accepted as a good starting point for the CG
of a conventional tailed aircraft.
* Static Margin is the %MAC that CG is ahead of Neutral Point, with a
typical range of 5% to 15% as a good starting point.
Lower static margins indicate less static stability (greater elevator
authority), while higher margins indicate more static stability (lesser
You can have too much static margin, which results in elevator stall at
take off and landing.
i r c r a f t S u p e r C a l c u l a t o r
6 . 1 (Mean Aerodynamic Chord, Neutral Point, Center
of Gravity, and Weight & Balance)
Neutral Point If
no changes are seen in results after updating an input field,
then click BOTH compute/refresh buttons.
the same units of measure (inches or feet) for all entries!
of Gravity (CG) is the point where the WEIGHT of the
aircraft is balanced. Neutral Point (NP) is the
point where the AERODYNAMIC FORCES generated by the wing
and tail are balanced.
CG 5% - 15% of MAC in front of NP creates a longitudinal
(pitch) stability called Static Margin. A lower
margin produces less stability and greater elevator
authority, while a higher margin creates more stability
and less elevator authority. Too much static margin
results in elevator stall at take off and landing.
25% - 35% MAC is generally accepted as a good range
for the CG of a conventional tailed aircraft where the AC
of the wing is at 25% MAC.
This calculator can be distributed by permission only simply
by copying the contents between the first and last
are fully contained within it. DO NOT REPURPOSE BY
email Dean A. Scott at dascott / at /
southern / dot / edu to obtain distribution clearance
and repurposing/reuse permission.
/ MAC Calculator adapted from the Public Domain. Neutral
Point and Weight & Balance Calculators developed by Dean
A. Scott (c) 2005, all rights reserved. Use with