Aviation Calculators
Weight and balance.
An aircraft's center of gravity is its total moment divided by its total weight. Enter the weight and arm of each item you are loading to get the total weight, total moment and CG, then compare them with the limits for your aircraft. The numbers shown are made-up examples, not any real aircraft. Runs in your browser; nothing is sent or stored.
Planning aid, not for flight operations
This tool is for study, trip planning and curiosity. It is not approved flight-planning or performance data. For an actual flight, use the aircraft's approved Pilot's Operating Handbook or Aircraft Flight Manual, current weather and charts, and your own judgement as pilot in command. Results can differ from your aircraft's real figures.
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Result
Fill the form and press Calculate.
Worked example
Made-up example numbers (not a real aircraft): empty aircraft 1,500 lb at 85.0 in (127,500 in-lb); pilot and front passenger 340 lb at 80.5 in (27,370 in-lb); rear passengers 170 lb at 118.1 in (20,077 in-lb); baggage 40 lb at 142.8 in (5,712 in-lb); fuel 180 lb at 95.0 in (17,100 in-lb). Total weight is 2,230 lb, total moment is 197,759 in-lb, and the CG is 197,759 ÷ 2,230 = 88.68 in. Against a 2,400 lb maximum weight and a CG range of 82.0 to 91.0 in, the weight is 170 lb under the maximum and the CG is within limits with 2.32 in to the nearest limit. The 180 lb of fuel is 30 gallons at 6 lb per gallon.
How it works
The FAA handbook defines the moment as an item's weight multiplied by its arm, the horizontal distance from the datum. Add up all the weights and all the moments; then CG = total moment ÷ total weight, measured from the same datum. Use the arm and unit system that your aircraft's weight and balance data use (typically pounds and inches).
The CG limits are the forward and aft points within which the CG must fall. On many aircraft they change with weight, so enter the limits that apply at the weight you are loading. The tool checks the CG against the forward and aft numbers you give it and the weight against the maximum you give it. It does not draw the envelope and does not know your aircraft. Leave a row blank if you are not using it. Gasoline is about 6 pounds per gallon, as the handbook notes.
Sources (each opened 2026-10-08): FAA, Pilot's Handbook of Aeronautical Knowledge, Chapter 10: Weight and Balance.
FAQ
How do you calculate center of gravity for an aircraft?
Multiply each item's weight by its arm to get its moment, add all the moments and all the weights, then divide the total moment by the total weight. The FAA handbook describes exactly this: determine the CG by dividing the total moment by the total weight.
What is an arm?
The arm (moment arm) is the horizontal distance from the datum to the item, as the FAA handbook defines it. Items ahead of the datum have negative arms; the tool accepts negative arms.
Where do I find the empty weight and arm?
In the aircraft's weight and balance records and flight manual. The numbers prefilled here are examples only and do not describe any real aircraft.
How much does fuel weigh?
The FAA handbook says gasoline weighs about 6 pounds per gallon, so 30 gallons is about 180 lb. Fuel also moves the CG, so check it for takeoff and again with the fuel you will have at landing.
What are the CG limits?
The FAA handbook describes them as the specified forward and aft points within which the CG must fall. Take them from the flight manual for your aircraft and loading.
Can I use this to load my aircraft for flight?
No. It is a learning and planning aid. Use the approved weight and balance data for your aircraft and the loading form your instructor or operator uses.