Free jump height calculator

Estimate jump height from flight time or count frame intervals in your video. No account needed.

How to time a jump from video

1. Film from the side at hip height with the feet clearly visible. Use the original clip and check its capture frame rate in the camera settings or recording metadata.
2. Step through the clip. Take-off is when the last foot leaves the ground; landing is when the first foot touches down. Each event falls between two frames: choose the first fully airborne frame for take-off and the first contact frame for landing, consistently across tests.
3. Subtract the take-off frame number from the landing frame number. Frames 100 to 160 span 60 elapsed intervals, not 61. Do not count both endpoint images as extra time.
4. Enter those intervals and the original capture rate. Flight time in seconds is intervals ÷ capture fps. If the original rate is unknown, do not substitute the player's playback rate.

Worked example

A jump spans 60 frame intervals in footage captured at 120 fps. Flight time is 60 ÷ 120 = 0.5 seconds, or 500 ms. Using h = g × t² ÷ 8 with g = 9.81 m/s² gives 0.3066 metres: 30.7 cm (12.1 inches). Both input methods above give this estimate.

A 120 fps recording played at 30 fps is four times slower. Use 120 fps with the original frame intervals; using 30 would stretch the flight time fourfold and the height sixteenfold. An export may duplicate or drop frames: count intervals in the original capture, not an edited slow-motion copy.

How much confidence to put in the number

At 30 fps one interval is 33.3 ms; at 120 fps it is 8.3 ms. Uncertainty of one frame at each end can change flight time by up to two intervals. For a 500 ms jump at 120 fps, that gives roughly 28.6–32.7 cm. More decimal places do not remove frame uncertainty.

The formula assumes the centre of mass is at the same height at take-off and first landing contact. Match body posture at those moments; tucked legs or landing with more bent knees can lengthen flight time and overestimate height. Never force a stiff landing for a number: reject a mismatched trial and repeat with a natural, consistent technique.

These are uncalibrated estimates, not laboratory measurements or diagnostic results. The analysis has been tested against synthetic jumps, not calibrated against a jump mat or force plate. Compare trials with the same setup, frame rate and technique.