Free Online Weight and Balance Calculator

Start with your specific aircraft's basic empty weight and empty weight arm from the official weight and balance record — not a generic number from the POH. Add each loading station's weight (pilot, passengers, baggage, fuel) multiplied by its arm to get the moment. Sum all weights for total weight and all moments for total moment. Divide total moment by total weight to get the CG position in inches aft of datum. Finally, plot the CG and weight on the CG envelope chart in the POH to verify it falls within limits.

The CG (Center of Gravity) envelope is a chart in the Pilot's Operating Handbook that defines the approved range of CG positions at various aircraft weights. It exists because the aircraft was flight-tested only within these limits. If the CG is too far forward, the nose becomes heavy, stall speed increases, and elevator authority may be insufficient for flare or rotation. If the CG is too far aft, the aircraft loses longitudinal stability and may become unrecoverable from a stall or spin. Always confirm your loading places the CG within the approved envelope before flight.

Flying outside weight and balance limits is extremely dangerous and violates FAR 91.9. An overweight aircraft requires longer takeoff rolls, climbs more slowly, has higher stall speeds, and may not clear obstacles. An aircraft loaded outside its CG range may have degraded stability, difficulty recovering from unusual attitudes, or could become completely uncontrollable. The pilot-in-command is solely responsible for ensuring the aircraft is loaded within all applicable limits before every flight.

Every certificated aircraft has an individual weight and balance record, typically found in the aircraft's maintenance records or equipment list. This is NOT the same as the generic empty weight printed in the POH — it reflects your specific aircraft including all modifications, paint, avionics upgrades, and equipment changes since manufacture. After any modification, the A&P mechanic must update the weight and balance record. Always use the most recent data sheet for your calculations.

The Cessna 172S Skyhawk SP has a maximum takeoff weight of 2,550 lbs and a maximum ramp weight of 2,558 lbs. The normal category CG range runs from approximately 35.0 inches aft of datum at lighter weights to 47.3 inches at maximum gross weight, with the forward limit shifting aft as weight increases. The utility category envelope is more restrictive, allowing a maximum weight of 2,200 lbs with a CG range of roughly 35.0 to 40.5 inches. Always verify against your specific aircraft's POH, as limits can vary by serial number and installed equipment.

Ramp weight (also called taxi weight) is the total weight of the aircraft when it begins to taxi, including all fuel. Takeoff weight is the ramp weight minus the fuel burned during engine start, taxi, and run-up — typically 1 to 2 gallons for a training aircraft. The Cessna 172S, for example, has a maximum ramp weight of 2,558 lbs but a maximum takeoff weight of 2,550 lbs, giving an 8-lb allowance for taxi fuel burn. This calculator accounts for both so you can verify you are within limits at each phase.

Standard aviation gasoline (100LL avgas) weighs 6.0 pounds per US gallon. This is the standard value used in weight and balance calculations for piston-engine training aircraft like the Cessna 172, Piper PA-28 Warrior, Cessna 152, and Diamond DA40. Jet-A fuel, used in turbine aircraft, weighs approximately 6.7 lbs per gallon. Always use 6.0 lbs/gal for avgas in your weight and balance worksheet.

Yes. This calculator has an Imperial/Metric toggle. Imperial uses pounds, inches, and US gallons; Metric uses kilograms, metres, and litres. The underlying aircraft data and limits are the same — only the display and input units change — so flight schools outside the United States can work in the units printed on their loading sheets. Switch units at any time and every field, result, and the CG envelope chart updates instantly.

ZFW (zero-fuel weight) is the aircraft loaded with crew, passengers, and baggage but no usable fuel. TOW (takeoff weight) is the ZFW plus the fuel on board at takeoff. LW (landing weight) is the takeoff weight minus the trip fuel burned en route. Professional weight and balance always checks all three, because the center of gravity moves as fuel burns off. This calculator plots ZFW, TOW, and LW on the CG envelope and shows the line the CG travels along during the flight.

Landing weight equals takeoff weight minus trip fuel — the fuel burned between takeoff and landing. To find it, enter any two of takeoff fuel, trip fuel, and reserve fuel in the fuel plan; the calculator derives the third (reserve = takeoff − trip) and computes the landing weight and landing CG automatically. Because fuel burns from a fixed tank position, the CG moves in a straight line from the takeoff point to the landing point — both must stay inside the approved envelope.

Yes. Enter your name and email and Aviatize will send a printable PDF worksheet of your calculation — the fuel plan, zero-fuel, takeoff and landing weights and CG, the loading breakdown, and the CG envelope chart with your points plotted. It is intended as a reference; always verify against your aircraft's official POH and individual weight and balance record before flight.

Yes, this calculator is completely free to use with no signup or account required. It supports eight common training aircraft: Cessna 152, Cessna 172S Skyhawk SP, Cessna 172R Skyhawk, Cessna 182T Skylane, Piper PA-28-161 Warrior III, Piper PA-28-181 Archer III, Piper PA-44-180 Seminole, and Diamond DA40 Diamond Star. The tool is provided by Aviatize for educational and reference purposes — always verify your results against the aircraft's official Pilot's Operating Handbook and individual weight and balance record before flight.