About the Vertical Jump Calculator
This vertical jump calculator turns a jump test into two useful numbers: how high you jumped and how much power your legs produced. Enter your standing reach and the highest point you touched (the classic wall or Vertec test), or the flight time from a jump mat or phone app, and the calculator works out jump height.
It then estimates peak power with the Sayers equation, the most widely used formula for converting jump height and body mass into watts, and shows the older Harman equation for comparison. Coaches use peak power and power per kilogram to compare athletes of different sizes and to track training for basketball, volleyball, sprinting and football.
Hang-time measurements assume you take off and land in the same body position; tucking the legs on landing inflates the result. The power equations were developed on college-age adults, so treat the watts as an estimate rather than a force-plate measurement.
With the default inputs, the vertical jump height (your units) is 55. Change any value above to recalculate instantly.
How to use the vertical jump calculator
- 1Pick metric or imperial units.
- 2Choose how you measured: reach test, flight time, or a known jump height.
- 3Enter your measurements and body weight.
- 4Read jump height, Sayers peak power and power per kilogram.
Formula and method
Jump height is the difference between the highest point touched in the jump and your flat-footed standing reach. From flight time, projectile motion gives h = g·t² ÷ 8 (with g = 9.81 m/s²), since you spend half the flight rising and half falling. Take-off velocity is √(2gh).
Peak power uses the Sayers et al. (1999) regression: 60.7 × jump height in cm + 45.3 × body mass in kg − 2055. It was derived from squat jumps measured on a force platform in 108 college-age men and women; applied to countermovement jumps it overestimated peak power by only about 2.7%, so the authors recommended it for both. The Harman et al. (1991) equation, 61.9 × h + 36.0 × mass − 1822, is shown for comparison; Sayers found their own equation more accurate. (Some websites print Harman with + 1822, which gives implausibly high values.) Both are estimates of the force-plate value.
- h
- Vertical jump height
- t
- Flight (hang) time in seconds
- g
- Gravitational acceleration, 9.81 m/s²
- PP
- Estimated peak power in watts
Worked examples
Reach test: 230 cm standing, 285 cm touch, 80 kg
Jump height is 285 − 230 = 55 cm. Sayers: 60.7 × 55 + 45.3 × 80 − 2055 = 4,908 W, or 61.3 W/kg. Harman gives a lower 4,463 W.
0.6-second flight time on a jump mat, 75 kg
h = 9.81 × 0.6² ÷ 8 = 0.441 m, or 44.1 cm. Sayers: 60.7 × 44.145 + 45.3 × 75 − 2055 ≈ 4,022 W.
Imperial: 28-inch vertical at 190 lb
28 in = 71.12 cm and 190 lb = 86.18 kg. Sayers: 60.7 × 71.12 + 45.3 × 86.18 − 2055 ≈ 6,166 W, about 71.5 W/kg.
Frequently asked questions
What is a good vertical jump?+
Many untrained adult men jump around 40–50 cm (16–20 in) and women around 30–40 cm (12–16 in). Trained basketball and volleyball players often exceed 60–70 cm (24–28 in), and elite jumpers go higher still.
What is the Sayers equation?+
It is a regression published by Sayers and colleagues in 1999 that estimates peak leg power from countermovement jump height and body mass: peak power (W) = 60.7 × jump height (cm) + 45.3 × body mass (kg) − 2055.
How accurate is hang time for measuring vertical jump?+
Flight-time methods are accurate if you land in the same extended position you took off in. Bending your knees or tucking before landing lengthens flight time and can overstate jump height by several centimetres.
Should I use a countermovement or squat jump?+
The Sayers equation was derived from squat jumps but works for countermovement jumps too (about 2.7% higher in the original study). Most tests and norms use the countermovement jump — a quick dip and explode, with or without an arm swing. Keep the technique consistent between tests so results are comparable.
How can I increase my vertical jump?+
Combine heavy lower-body strength work (squats, deadlifts, hip thrusts) with plyometrics such as box jumps and depth jumps, and reduce excess body fat. Most athletes see gains over 8–12 weeks of consistent training.