Weight & Balance Calculator
Verify your aircraft is within weight and CG limits before every flight. Select an aircraft, enter your loading, and see your position on the envelope diagram instantly.
| Station | Weight (lbs) | Arm (in) | Moment | |
|---|---|---|---|---|
| Aircraft Empty Weight | 1,680 | 40.5 | 68,040 | |
| Front Seats | 0 | |||
| Rear Seats | 0 | |||
| Fuel (gal)(40 gal = 240 lbs) | max 56 gal | 11,520 | ||
| Baggage Area 1 | max 120 lbs | 0 | ||
| Baggage Area 2 | max 50 lbs | 0 | ||
| TOTALS | 1,920 | 41.4 | 79,560 |
WITHIN LIMITS
Total Weight
1,920 lbs
Max: 2,550 lbs
CG Location
41.4 in
Range: 35.0 - 47.3 in
Total Moment
79,560
lb-in
CG Envelope Diagram
Test Your Knowledge: FAA Weight & Balance Question
Weight and balance calculations appear on every FAA checkride. Can you solve this one?
Weight and balance questions appear on every FAA written exam and checkride. Practice with 1,000+ real exam questions.
Start your exam prep — $7.49/mo (50% off)How to Calculate Aircraft Weight and Balance
Weight and balance is one of the most critical preflight calculations a pilot must perform. An aircraft loaded beyond its maximum gross weight or outside its center of gravity (CG) envelope can be dangerously difficult or impossible to control.
The Weight & Balance Formula
The basic formula is straightforward: for each item in the aircraft, multiply its weight by its arm (distance from the datum) to get its moment. Then sum all weights and all moments. Divide total moment by total weight to get the CG location. Finally, verify the total weight does not exceed maximum gross weight and the CG falls within the approved envelope from your POH.
Key Terms
- Datum — The reference point from which all arms are measured (set by the manufacturer).
- Arm (station) — Horizontal distance from the datum to the CG of an item, in inches.
- Moment — Weight multiplied by arm (lb-in). Represents the turning force of an item about the datum.
- CG (Center of Gravity) — The point where the aircraft balances. CG = Total Moment / Total Weight.
- CG Envelope — The manufacturer-defined range of allowable CG positions at different weights.
Fuel Weight Conversion
Aviation gasoline (avgas) weighs approximately 6 lbs per gallon. Jet-A fuel weighs about 6.7 lbs per gallon. This calculator uses 6 lb/gal for avgas. Always check the actual weight for your fuel type.
Why CG Matters
A forward CG increases stability but requires more elevator authority and increases stall speed. An aft CG decreases stability and can lead to an unrecoverable stall. Both overloading and CG-out-of-limits conditions are among the leading causes of general aviation accidents.