Weight and Balance (Expanded) Calculator

This calculator applies the standard moment method across five loading stations — empty aircraft, front seats, rear seats, baggage, and fuel — to find total weight and center of gravity for a specific load. Each station contributes a moment equal to its weight times its arm (the station's distance from the aircraft's datum reference point, taken straight from the POH's weight-and-balance data); summing all five moments and dividing by summed weight gives the CG location in inches from datum, exactly as it would be calculated by hand on a loading form. Fuel is converted from gallons to weight at a fixed 6 pounds per gallon, the standard planning figure for aviation gasoline (actual avgas density varies slightly with temperature, but 6 lb/gal is the number POH performance charts are built around).

Beyond the raw numbers, the calculator checks two limits independently: total weight against maximum gross weight, and CG against both forward and aft limits inclusive of the boundary values themselves, then reports a single pass/fail flag only when both checks succeed. It also reports useful load — max gross weight minus empty weight and fuel weight — which tells you how much payload (people plus baggage) remains available at a given fuel load before you hit gross weight, independent of whether that payload happens to keep CG in limits. A common error is treating a passing weight check as sufficient: an airplane can be safely under gross weight while still outside its CG envelope, particularly with an empty rear seat and full baggage, so both outputs need to be checked together.