Weight and Balance Calculator for Aircraft

Operating outside the approved CG envelope is extremely dangerous and violates FARs. A CG too far forward makes the aircraft nose-heavy, requiring excessive elevator force to flare during landing and potentially leading to a nosewheel-first touchdown. It also increases stall speed. A CG too far aft makes the aircraft unstable and difficult to control, with reduced stall warning and potential for unrecoverable spins. The aircraft may become uncontrollable in pitch. Always redistribute weight or reduce load to bring CG within limits before flight.

Moment arms for each loading station are listed in Section 6 (Weight & Balance) of your aircraft's POH or Flight Manual. They are measured in inches from the datum reference point (typically marked on the aircraft firewall or leading edge). Each model and sometimes each serial number can have different moment arms due to equipment variations, so use the data specific to your aircraft's serial number. The loading graph or table in the POH shows exact arm values for pilot, copilot, passengers, baggage compartments, and fuel tanks.

Yes, FAR 91.9(a) requires the pilot-in-command to comply with operating limitations, including weight and balance. You must perform a weight and balance calculation before each flight when loading changes from your last calculation. Even if you fly the same aircraft regularly, passenger weights, baggage, and fuel loads vary between flights. Many pilots maintain a W&B worksheet for each flight in their records. For commercial operations, W&B calculations are mandatory documentation retained in the flight records.

As fuel burns during flight, total weight decreases and CG position shifts. The direction of shift depends on fuel tank locations relative to the CG. If tanks are ahead of the CG, the CG moves aft as fuel burns. If tanks are aft of the CG, it moves forward. Most aircraft have fuel tanks positioned so CG remains within limits throughout the flight, but on longer flights with significant fuel burn, it's good practice to verify CG will remain in limits at landing weight. Some aircraft have specific fuel burn procedures to maintain proper CG.

The center of gravity (CG) is where the aircraft's total weight acts, determined by the distribution of mass. The center of lift (also called center of pressure) is where the wing's total lift force acts, which varies with angle of attack. For stable flight, the CG must be forward of the center of lift. The horizontal stabilizer generates a downward force to balance the moment created by this offset. If CG moves too far aft, it approaches or exceeds the center of lift, reducing stability and potentially making the aircraft uncontrollable.

The FAA allows standard weights for commercial operations (adults: 190 lbs summer/195 lbs winter, children: 82 lbs) but recommends using actual weights when known for greater accuracy. For Part 91 operations, actual weights are strongly recommended and required if the pilot suspects standard weights would result in inaccurate calculations. Using actual weights is always more accurate and safer. For small aircraft with limited useful load, a few pounds can make the difference between being within or outside limits. Consider using actual weights especially when carrying larger passengers or maximum loads.

Basic Empty Weight (BEW) is the weight of the aircraft including all permanently installed equipment, unusable fuel, and full operating fluids (oil, hydraulic fluid). It's determined by actually weighing the aircraft on calibrated scales, typically at three points (nose and two main wheels). The most recent weighing is documented in the aircraft's weight and balance report, usually found in the POH or aircraft logbooks. BEW changes whenever equipment is installed or removed, requiring a new weighing. Major alterations like avionics upgrades require updated W&B data.