Gravity / Free Fall Calculator
Calculate free fall time and impact velocity from height, or find height from fall time.
Supports both metric and imperial units.
Free Fall Result
Free Fall Equations (ignoring air resistance, using g = 9.81 m/s²):
From height:
Time = √(2h / g)
Impact Velocity = √(2gh)
From time:
Height = ½gt²
Impact Velocity = gt
Unit conversions:
- Metric: Height in meters, velocity in m/s
- Imperial: Height in feet (1 ft = 0.3048 m), velocity in ft/s
Key values:
- g (metric) = 9.81 m/s²
- g (imperial) = 32.17 ft/s²
- Terminal velocity of a human ≈ 53 m/s (120 mph) — air resistance limits actual fall speed
Examples:
- Drop from 10 m: hits in ~1.43 s at ~14 m/s (31 mph)
- Drop from 100 m: hits in ~4.52 s at ~44.3 m/s (99 mph)