Use this calculator for flight-planning study or a first-pass cross-check when all inputs describe the same aircraft, atmospheric condition, and phase of flight.

CG position (in)

Center of gravity position aft of the datum.

LEMAC position (in)

Leading edge of the MAC, aft of the same datum.

MAC length (in)

Length of the mean aerodynamic chord.

Express the center-of-gravity position as a percentage of the mean aerodynamic chord. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

% MAC (%)

CG position as percent of the MAC.

• Do not use a generic calculator in place of the current aircraft flight manual, approved performance data, operating limitations, NOTAMs, weather, or regulations. Real performance changes with configuration, runway condition, altitude, temperature, wind, loading, and technique.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Cross-check the result against the aircraft flight manual or approved planning system, then apply the required safety margins. Keep signed wind, heading, altitude, speed, and fuel conventions explicit.

• CG Shift Fuel Calculator

  Calculate the center-of-gravity shift after all specified fuel is burned from its stated arm.

• Weight Shift CG Calculator

  Compute how far the center of gravity moves when a load is shifted a given distance.

• Center of Gravity Calculator

  Locate the aircraft center of gravity by dividing total moment by total weight.