Weight & Balance Calculator
Calculate total weight, center of gravity, and moments for aircraft loading. Verify CG is within the envelope before every flight.
About this calculator
Weight and balance comes down to two questions: is the aircraft too heavy, and is the load positioned so the center of gravity stays inside the envelope? This calculator answers both using the standard moment method — each loading station (empty aircraft, front seats, a second row, an optional third row, fuel, and baggage) has a weight and an arm (its distance from a reference datum), and the moment at each station is weight times arm. Summing all the weights gives total weight, summing all the moments gives total moment, and dividing total moment by total weight gives the CG position in inches from the datum. The calculator flags an overweight condition against your entered max gross weight, and separately flags whether CG falls forward or aft of the limits you enter (both are configurable per aircraft, since every type has different numbers from its POH).
Fuel weight is calculated at a fixed 6.0 lb/gal, the standard figure for avgas 100LL — if you're flying something on Jet-A at 6.7 lb/gal, adjust the gallons entered or expect the fuel weight to read slightly low. Useful load (max gross minus empty weight) and remaining payload after fuel are broken out to help with quick loading decisions, such as how much baggage you can add once fuel is topped off. An aft-CG exceedance is flagged as the more dangerous condition, since it can make an aircraft difficult or impossible to recover from certain flight attitudes — always verify the actual arms and limits against your specific aircraft's current W&B sheet, not the example defaults shown here.
Inputs
C172: 40–53 gal, C182: 65–87 gal
C172: 2,550 lb, C182: 3,100 lb, PA-28: 2,440 lb
Results
Total Takeoff Weight
1,958 lb
≈ 11 adults
Center of Gravity (CG)
73.1 in
≈ 12 smartphones
CG Status
AFT of Limit
How to Use This Calculator
- Enter your aircraft's empty weight and arm from the W&B sheet (found in the POH).
- Enter weights for pilot, passengers, fuel, and baggage.
- Enter the arm (station) for each loading station from the POH loading diagram.
- Verify the CG is within limits and total weight doesn't exceed max gross.
How the result changes across these scenarios
| Scenario | Total Takeoff Weight | Center of Gravity (CG) | CG Status |
|---|---|---|---|
| Solo Full Fuel | 2,018 lb | 72.8 in | AFT of Limit |
| Full Pax, Reduced Fuel | 2,400 lb | 72 in | AFT of Limit |
| Heavy Load Check | 2,738 lb | 70.7 in | AFT of Limit |
What each input means
- Aircraft Empty Weight
- Basic empty weight from your aircraft's weight and balance sheet (includes unusable fuel and oil).
- Empty Weight Arm
- CG arm (station) for empty weight from W&B sheet.
- Pilot & Front Passenger
- Combined weight of pilot and front seat passenger.
- Front Seats Arm
- Arm (station) for front seats from POH loading diagram.
- Rear Passengers (Row 2)
- Combined weight of rear seat passengers.
- Rear Seats Arm
- Arm for rear seats from POH.
- Additional Passengers (Row 3)
- Weight in a third row if applicable. Set to 0 for 4-seat aircraft.
- Row 3 Arm
- Arm for third row seats.
- Fuel
- Usable fuel in gallons. Avgas weighs 6.0 lb/gal; Jet-A weighs 6.7 lb/gal.
- Fuel Tank Arm
- Arm for fuel tanks from POH.
- Baggage / Cargo
- Weight of baggage and cargo. Check POH for baggage compartment weight limits.
- Baggage Arm
- Arm for baggage compartment from POH.
- Max Gross Weight
- Maximum takeoff weight from POH. C172S = 2,550 lb, C182T = 3,100 lb.
- Forward CG Limit
- Forward CG limit from POH W&B envelope.
- Aft CG Limit
- Aft CG limit from POH W&B envelope.
What each result means
- Total Takeoff Weight
- Sum of all weights. Must not exceed max gross weight.
- Center of Gravity (CG)
- CG position aft of datum. Must be within forward and aft limits.
- CG Status
- Whether CG is within the allowable envelope.
- Useful Load
- Max gross weight minus empty weight — the total you can carry (people + fuel + cargo).
- Remaining Payload (after fuel)
- How much people + cargo weight you can still add after fuel.
- Excess Weight
- How much over max gross weight (0 if within limits).
How this is calculated
Worked example, using the default values
- Fuel WeightFuel Weight = Gallons × 6 lb/gal (avgas)48 × 6 = 288 lb
- Total WeightTotal = Empty + Pilot + Pax + Rear + Fuel + Baggage1500 + 170 + 0 + 0 + 288 + 0 = 1,958 lb
- Total MomentMoment = Σ (Weight × Arm) for each station123,000 + 6,290 + 0 + 0 + 13,824 + 0 = 143,114 lb·in
- Center of Gravity (CG)CG = Total Moment ÷ Total Weight143,114 ÷ 1,958 = 73.1 inches aft of datum
Engine last updated . Checked against 1 independently-derived test — how we verify calculators. Built by Paul Gunder, a software engineer, not a licensed financial, medical, or legal professional.
Frequently Asked Questions
How exactly is center of gravity calculated from these inputs?
Each loading station — empty aircraft, front seats, row 2, row 3, fuel, and baggage — has its weight multiplied by its arm (distance from the reference datum) to get a moment. All the weights are summed to get total weight, all the moments are summed to get total moment, and CG is total moment divided by total weight.
Why is fuel weight calculated at exactly 6 lb per gallon?
The calculator uses 6.0 lb/gal, the standard figure for avgas 100LL. If your aircraft burns Jet-A instead (6.7 lb/gal), the calculated fuel weight will read slightly low for the gallons entered — adjust the fuel quantity or account for the difference manually.
What's the difference between useful load and remaining payload after fuel?
Useful load is max gross weight minus empty weight — everything you can add, including fuel, people, and cargo. Remaining payload after fuel subtracts your entered fuel weight from useful load, showing what's left for people and baggage once the tanks are filled to your entered quantity.
Why does the calculator treat an aft CG exceedance as more dangerous than a forward one?
An aircraft with CG too far aft can become longitudinally unstable and, in some cases, unrecoverable from a stall or spin, since there's less elevator authority available to pitch the nose back down. A forward CG exceedance mainly costs elevator authority during flare and slow flight — less pleasant but generally more survivable — which is why the calculator's explanation carries a stronger warning for the aft case.
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