Weight and Balance: How to Calculate CG (Worked Example)
What you'll learn: compute total weight and center of gravity (CG), and check both against the limits in your POH. Source: FAA Weight & Balance Handbook, PHAK Ch. 10.
The three numbers
- Weight (lb)
- Arm: distance from the datum (inches)
- Moment = weight × arm (lb-in)
CG = total moment ÷ total weight. Useful weights: avgas about 6 lb/gal, oil about 7.5 lb/gal.
Worked example (made-up airplane; use your own POH)
| Item | Weight (lb) | Arm (in) | Moment |
|---|---|---|---|
| Empty weight | 1,500 | 39.0 | 58,500 |
| Pilot + front passenger | 340 | 37.0 | 12,580 |
| Fuel 40 gal | 240 | 48.0 | 11,520 |
| Baggage | 50 | 95.0 | 4,750 |
| Total | 2,130 | 87,350 |
CG = 87,350 ÷ 2,130 ≈ 41.0 in. Check 2,130 lb and 41.0 in against the POH envelope. Then check again for landing weight after fuel burn.
Why it matters
- Forward CG: more stable, higher stall speed, harder to flare, needs more elevator.
- Aft CG: less stable, lower stall speed, harder stall/spin recovery. Beyond the aft limit it can be uncontrollable.
- Overweight: longer takeoff, slower climb, higher stall speed, structural risk.
Check yourself
2 questions. Pick an answer to see why it's right or wrong.
Sources, review & change history
- Published
- Oct 16, 2026
- Last source review
- Not yet re-checked against primary sources
- Reviewer
- No independent reviewer yet. Written by Jackson, a student pilot, not a CFI.
- Scope
- Weight and balance concepts; limits and arms come from your aircraft's POH and W&B records.
Primary sources
Changes
- Oct 17, 2026: First published.
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