Beep Test Calculator — VO2 Max from Shuttles

The 20 m multistage fitness test — the beep test, the shuttle run — estimates aerobic capacity from how long you can hold a pace that keeps accelerating. Enter your total shuttles completed, not the level you reached:

The protocol

1. Mark two lines 20 m apart on a flat, non-slip surface.
2. Start the audio. The opening pace is 8.5 km/h, and it rises 0.5 km/h every minute — each of those minutes is a level.
3. Run line to line, aiming to have a foot on or past the line as each beep sounds.
4. The test ends when you fail to reach the line in time twice consecutively. Count every completed 20 m length up to that point.

Getting the ending right matters: one missed beep is a warning, not a result. A protocol stopped on the first miss systematically undercounts.

The equation, and who it was measured on

This calculator uses the Kilding equation:

VO2 max (mL/kg/min) = 0.38 × total shuttles completed + 25.98

Sixty shuttles gives 0.38 × 60 = 22.8, plus 25.98 — about 48.8 mL/kg/min.

Know its pedigree before you quote the output. Kilding, Aziz and Teh measured actual oxygen uptake during the multistage fitness test in 26 elite male intermittent-sport athletes and derived this regression from that group. The fit was moderate: R = 0.69, R² = 0.48, with a standard error of estimate of 4.9 mL/kg/min (8.3%). That is a narrow, fit, all-male sample, and a ±5 mL/kg/min band around whatever number appears above.

The study’s motivating finding is the more useful one. Both established prediction methods came out significantly lower than measured VO2 max — by 9.3% and 13.2% — in athletes whose true average was 59.1 mL/kg/min (SD 6.6). If you are well trained, expect any beep-test estimate to sell you short.

Note also that the equation does not pass through zero: it returns about 26 mL/kg/min at zero shuttles, which is an artifact of a straight line fitted over a narrow range, not a claim about someone who cannot run.

Different calculators, different answers

There is no single beep test formula, and the differences are not rounding. The three in circulation:

Equation	Input it wants
Kilding (used here)	Total shuttles completed
Ramsbottom	Level plus shuttles at that level
Leger	Final running speed in km/h

Topend Sports, the source the original version of this page cited for the Kilding equation, now runs its own calculator on Ramsbottom instead. So two pages can both be honest, both cite real literature, and hand you VO2 max values several points apart. When you compare a result over time, compare it against the same equation — never against a screenshot from a different site.

Why the test caught on

Twenty meters of floor and an audio file, and you can test a whole squad at once. Nothing else in aerobic testing is that cheap, which is why the beep test ended up in schools, academies and team preseasons worldwide despite estimating rather than measuring. The tradeoff is the one above: it is an estimate with a real error band, made on a specific population, that gets worse the further you sit from that population.

For a broader look at aerobic capacity estimates, see the VO2 max calculator. For the anaerobic side of the same battery, run the Illinois agility test, or go back to the fitness test calculator.

This content is informational and does not replace evaluation by an exercise professional.