G-Force Calculator — Linear & Centripetal Acceleration

Formula

How this is calculated

G-force is the ratio of a body's acceleration to standard gravitational acceleration g₀ = 9.80665 m/s² (the exact value defined by the International Bureau of Weights and Measures). A person standing at rest experiences 1 g pointing downward. Any additional acceleration — from a rocket launch, a car braking hard, or a rollercoaster loop — adds to or subtracts from this perceived weight.

For linear acceleration (a rocket burning, a car accelerating forward, a braking manoeuvre), g-force equals the acceleration in m/s² divided by g₀. For circular motion — a banked turn, a loop, an aircraft pulling up — the centripetal acceleration is v²/r, where v is speed in m/s and r is the turn radius in metres. That centripetal value is then divided by g₀ to give the g-load.

Human tolerance depends on direction (positive g — head to foot — is tolerated less well than chest-to-back), duration, and training. Untrained individuals may experience G-LOC (g-force induced loss of consciousness) above roughly 4–6 g sustained. Fighter pilots in anti-g suits trained with the AGSM (anti-g straining manoeuvre) can tolerate 9 g briefly. These reference bands are approximate; individual limits vary widely.