Acceleration is how fast velocity changes. The SI unit is the metre per second squared (m/s²); the imperial unit is ft/s²; g expresses multiples of Earth's gravity (1 g = 9.80665 m/s²); the Gal is used in geophysics (1 cm/s²); and km/h/s and mph/s describe how quickly speed builds. This converter rebases through m/s².
Reviewed: June 20, 2026 · Author: Naveen P N, Founder — AI Calculator · Verified against: SI definitions (g = 9.80665, ft = 0.3048 m), recomputed in code.
How the conversion works
Each unit's factor in m/s²: ft/s² = 0.3048, g = 9.80665, Gal = 0.01, km/h/s = 0.277778, mph/s = 0.44704, m/s² = 1. Multiply by the from-factor to land in m/s², then divide by the to-factor. The g factor is exact by the international definition of standard gravity.
Worked examples
1 g to metres per second squared:
10 m/s² to feet per second squared:
100 km/h per second to m/s²:
So 1 g is 9.81 m/s², 10 m/s² is about 32.8 ft/s², and gaining 100 km/h every second is roughly 27.8 m/s² — nearly 3 g.
Frequently Asked Questions
÷ 0.3048. 10 m/s² = 32.81 ft/s². Reverse: × 0.3048.
9.80665 m/s² (standard gravity). 2 g = 19.61 m/s²; 9.81 m/s² ≈ 1.0003 g.
1 cm/s² = 0.01 m/s², used in geophysics. 1 m/s² = 100 Gal.
1 mph/s = 0.44704 m/s². Gaining 10 mph/s = 4.47 m/s². 1 km/h/s = 0.277778 m/s².
No — a = Δv ÷ Δt is a separate calc. This converts units only.