Vertical jump test: jump height from video

An online tool for measuring vertical jump height from video or a phone camera. Height is calculated from flight time — the same quantity contact mats measure. The result comes with its error margin, take-off and landing are visible on the frames, and if the analysis gets it wrong or refuses, the jump can be marked by hand.

How to measure

Film the jump from the side

Phone at waist height, three to four meters away, the whole person in the frame. Slow motion is more accurate.

Upload a video or turn on the camera

The analysis runs in the browser; when filming with the camera, the jump appears right after landing.

Check the frames and save

The “Frames” tab shows take-off and landing; the result goes into the log or a PDF report.

Place a phone to the side, jump and check the take-off frame by frame

Jump videoA video from your phone. Slow motion is more accurate.

Waiting for video

How to film the jump

camera to the side
at waist height
3–4 meters
whole body in frame, even in the air
even light

0jumps

Who is jumping

Test

Height, cm Mass, kg

Both fields are optional. Height is used for the scale self-check (which also reveals slow-motion footage), mass for a power estimate with the Sayers formula.

Place the camera to the side at waist height, three to four meters away, so the person fits in the frame both in the air and at the lowest point. Even light, clothing that stands out from the background, and the phone kept still.

Error from missing by one frame when marking a 40 cm jump by hand: 30 fps — 4.7 cm, 60 — 2.3, 120 — 1.2, 240 — 0.6. The automatic analysis looks for the edges between frames and errs less, but at 30 fps recognition noise causes more scatter and more refusals.

Recording slowdown

If the phone saved slow-motion video as regular video (240 fps played back as 30), set the factor. The tool usually suggests it on its own.

Announce the height aloud when filming with the camera

Press “Add to log” after a measurement — the result is saved with the name and test. The log is stored in this browser.

What exactly is calculated

While the feet are off the ground, the body is in free fall and the rise equals g·t²/8, where t is the flight time. A parabola is fitted through all airborne frames, and take-off and landing are found as the points where this parabola touches the ground-phase trajectory — between frames.

What the tool does not do

This is a single-camera measurement. A steep angle, a partly hidden body and clothing the color of the background make the analysis worse; a low jump at 30 fps offers no source of precision, and then the tool refuses rather than producing a nice-looking number. It does not replace a contact mat and does not deliver a verdict at a fitness test.

Features

A parabola through all airborne frames

Instead of two marks, a free-fall parabola runs through all airborne frames, and the edges of the flight are found as points of contact with the ground-phase trajectory, between frames.

Frame check and manual marking

Frames with a skeleton and ankle dots show take-off and landing. If you disagree, mark the first frame in the air and the first one on the ground, and the height is recalculated with an error of ±½ frame.

Error margin next to the number

The scatter is measured by repeating the calculation with added noise the size of the fit’s own residual. When there is nothing to measure with, the tool refuses rather than showing a plausible number.

Slow-motion footage is recognized

A 240 fps clip saved as regular video is stretched in time. The scale self-check based on the person’s height notices this and suggests a slowdown factor.

CMJ, Abalakov, SJ, repeated jumps and drop jump

The test is saved together with the result. For a set of jumps, the average height, drop-off by the end, ground contact time and the reactive strength index (RSI) are calculated.

Athlete log

Results are saved with the name and test, and the best one is marked with a star. The log exports to CSV, and a single measurement to a PDF report with a chart.

Questions and answers

Why is height calculated from flight time rather than from how high the body rises in the video?

The rise in the video depends on the camera angle and on how the person holds their body, while flight time does not: as long as the feet are off the ground, the rise of the center of mass equals g·t²/8. Contact mats work with the same quantity, so the result can be compared with theirs. The rise in the frame is used only as a scale self-check.

Is regular 30 fps footage enough?

For measuring, yes: the edges of the flight are found between frames, not on a frame. But at 30 fps, body recognition noise affects the answer more: there is more scatter, and low jumps are refused more often. To track progress and for drop jumps, film in slow motion at 120–240 fps — the error margin next to the number will show the difference.

How can I check that take-off was found correctly?

Open the “Frames” tab: the “To take-off” and “To landing” buttons go to the right moment, the green bar under the frames marks the flight, and the yellow dots are the ankles. If an edge was picked wrongly, mark the first frame in the air and the first frame on the ground — the height will be recalculated, and in the log such a measurement is marked with an asterisk.

How is a CMJ different from the Abalakov jump?

Both are done with a countermovement, but in a CMJ the hands stay on the hips, while the Abalakov jump uses an arm swing, so it is usually higher. A result is only worth comparing with the same test: the log stores the test next to the height and marks the best result separately for each one.

I got several meters. What went wrong?

Most likely this is slow-motion footage the phone saved as regular video: time is stretched, and flight time along with it. The tool notices this from the person’s height and suggests a factor; if there is no suggestion, enter the athlete’s height or choose the factor in the “Filming” section.

Can this replace a contact mat?

No. A mat measures ground contact directly and depends neither on the camera angle nor on whether the person is visible. Here the same flight time is extracted from video and inherits its weaknesses — the angle, a partly hidden body, clothing the color of the background. On the other hand, all you need is a phone, and you get an error margin and a frame-by-frame check. As an aid in training, yes; as the judge at a fitness test, no.

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Who is this tool for?

🏃 Sports & Athletics

Published 12 Sep 2026 Updated 13 Sep 2026 Author: The Supreme