RunupLab

Free tool

Weight & Balance Calculator

Enter your empty weight and CG, then each loading station — front seats, rear seats, baggage, and fuel — with the arm it acts on, and read back total weight, center of gravity, and whether the loaded point sits inside the CG envelope. The chart plots your loaded point and the zero-fuel point against the envelope so you can see the load walk forward as you burn off fuel.

The method is the same for any light single: each station's moment is its weight times its arm; total moment divided by total weight is the CG; that CG is checked against the forward and aft limits interpolated at your weight. The numbers here default to a clearly-labeled PA-28-140 example— because empty weight, station arms, and the envelope are aircraft-specific, every field is editable. Use your own aircraft's weight-and-balance form and POH.

Empty aircraft

From your aircraft's actual weight-and-balance form — the example is a PA-28-140 (use your POH).

Load stations — weight & arm

Fuel at 6 lb/gal = 288 lb aboard. Arms are inches aft of the datum — edit them for your airframe.

Total weight1,914 lb
Center of gravity86.7 in
Envelope checkIN — within limits

Limits at 1,914 lb: CG must fall between 85.595.9 in. Max gross 2150 lb. Your CG is 86.7 in.

828486889092949698120014001600180020002200CG — IN AFT OF DATUMLBMAX GROSS 2150

loaded · zero fuel · max gross. Burning fuel walks the point from loaded toward the zero-fuel mark — check that it stays inside the whole way down. Verify against your aircraft's W&B form before flight.

More pilot tools

One of a growing set of free pilot tools. For how weight and balance fits into preflight planning and the regulations behind it, see the study guide.