Jump Height from Hang Time Calculator
When you jump straight up, the time your feet spend off the ground (hang time) is fixed by how high you rise, because gravity is constant. Half the hang time is the rise and half is the fall. From the projectile-motion equations, jump height equals gravitational acceleration times the square of hang time, divided by eight. Enter your hang time, and optionally adjust gravity, to find your vertical jump height in centimetres, metres and inches.
Jump height formula
h = g * t^2 / 8
where t = hang time, g = gravitational acceleration
derived from h = g * (t/2)^2 / 2
The jump is symmetric: the upward flight time is half the hang time. Substituting t/2 into the free-fall distance equation h = g(t/2)^2/2 simplifies to g t^2 / 8. Standard gravity is 9.80665 m/s squared.
Worked example
Hang time of 0.6 seconds at g = 9.80665: h = 9.80665 * 0.36 / 8 = 0.4413 metres = 44.13 cm = 17.37 inches.
Frequently asked questions
Why divide by eight?
Hang time covers both the rise and the fall, so the time to the peak is half the hang time. The free-fall distance is g times time squared over two; substituting half the hang time and simplifying gives g times hang time squared over eight.
How do I measure hang time?
Use a jump mat, a high-speed video frame count, or a phone app that times the airborne phase. Accuracy matters: because height depends on the square of time, small timing errors are amplified.
Does this work on other planets?
Yes. The gravity input is editable, so you can compute jump height under any gravitational acceleration. A smaller g for the same hang time yields a greater height.
Sources
- U.S. National Institute of Standards and Technology: standard acceleration of gravity.
Reviewed by the CalculatorHub team, edited by James Graham, 19 June 2026. See our methodology.