Aircraft Weight and Balance Calculator
Aircraft weight and balance calculations determine whether the aircraft's total weight and center of gravity (CG) are within the approved limits for safe flight. The CG must be within the manufacturer's forward and aft limits at takeoff, cruise, and landing. This calculator uses the moment method: each item's weight is multiplied by its arm (distance from datum) to give its moment; the CG is total moment divided by total weight. Enter up to six stations with their weights and arms.
Enter weight (lb) and arm (inches from datum) for each station. Leave unused rows at 0.
Weight and balance calculation method
Moment = Weight (lb) x Arm (in from datum)
Total Weight = sum of all weights
Total Moment = sum of all moments
CG = Total Moment / Total Weight (inches from datum)
The CG must satisfy: forward CG limit less than or equal to CG, and CG less than or equal to aft CG limit. Total weight must not exceed MTOW. This method is defined in FAA-H-8083-1 (Aircraft Weight and Balance Handbook). Always use your specific aircraft's POH for actual arms, weights, and limits.
Weight and balance best practices
- Always compute W&B before the first flight of the day and whenever loading changes.
- Verify fuel load: avgas weighs approximately 6.0 lb per US gallon.
- Account for fuel burn: as fuel is consumed, CG may shift forward or aft depending on tank location.
- Baggage: never exceed the baggage compartment weight limit even if total W&B is in limits.
- Zero-fuel weight: some aircraft have a maximum zero-fuel weight limit that must also be checked.
Aircraft weight and balance calculator: frequently asked questions
What is aircraft weight and balance?
Weight and balance (W&B) is the calculation that determines the total weight of the aircraft and the location of the center of gravity (CG). The CG must be within the manufacturer's approved envelope at all times. Flying outside the CG limits can make the aircraft uncontrollable. W&B calculations are required before every flight and are the pilot-in-command's legal responsibility under 14 CFR 91.9.
How is center of gravity calculated?
CG = Total Moment / Total Weight. Moment = Weight x Arm (distance from datum). You sum all the moments (weight x arm for each item), sum all the weights, and divide total moment by total weight to get the CG location in inches from datum. The result must fall within the forward and aft CG limits for the aircraft's weight.
What is the datum?
The datum is a fixed reference point established by the manufacturer, typically at or ahead of the nose of the aircraft. All arm distances are measured from this point. Some manufacturers use the firewall or the leading edge of the wing as the datum. The datum location is specified in the aircraft's type certificate data sheet.
What happens if the CG is too far forward?
A forward CG requires more up-elevator to maintain level flight, increasing drag. At the forward CG limit, the elevator may have insufficient authority to flare for landing. Very forward CG can lead to nose-heavy handling and inability to raise the nose at low speeds. The forward CG limit is primarily an elevator authority limitation.
What happens if the CG is too far aft?
An aft CG reduces longitudinal stability. The aircraft may be difficult to control and may pitch up unexpectedly. In extreme cases, the pilot cannot push the nose down, leading to an unrecoverable pitch-up. The aft CG limit is a stability and control limitation. Aft CG is more dangerous than forward CG and must be avoided.
Official sources
- FAA: Aircraft Weight and Balance Handbook (FAA-H-8083-1).
- FAA: 14 CFR 91.9 - Civil aircraft flight limitations.
Reviewed by the CalculatorHub team, edited by James Graham, 14 June 2026. See our methodology.