About the Vertical Jump Power
Strength and conditioning coaches and athletes use this calculator to estimate leg power output from a countermovement vertical jump, using only jump height and body mass rather than requiring a force plate, based on the Harman formula published by Harman and colleagues in 1991.
How It Works
Enter your vertical jump height in centimeters and your body mass in kilograms. The calculator runs those two numbers through two separate linear equations, one estimating peak power output at the most explosive instant of the jump, and one estimating average power output across the entire jump, giving two complementary views of the same effort from a single test.
Formula & Methodology
For a 55 cm jump at 80 kg body mass, peak power = 61.9 x 55 + 36.0 x 80 + 1822 = 3404.5 + 2880 + 1822 = 8106.5 W, and average power = 21.2 x 55 + 23.0 x 80 - 1393 = 1166 + 1840 - 1393 = 1613 W. Both equations are run independently from the same two inputs, so no additional measurements are needed beyond jump height and body mass.
Examples
A recreational athlete
A 55 cm jump at 80 kg body mass gives an estimated peak power of about 8107 W and average power of about 1613 W.
A lighter, higher-jumping athlete
A 65 cm jump at 65 kg body mass gives peak power = 61.9 x 65 + 36.0 x 65 + 1822 = 8185.5 W and average power = 21.2 x 65 + 23.0 x 65 - 1393 = 1480 W, showing how a lighter athlete can post similar peak power to a heavier one simply by jumping higher.
Advantages
- Estimates leg power output without needing a force plate or other specialized jump-testing equipment.
- Separates peak power from average power, giving two distinct views of the same jump effort.
- Uses only two easily measured inputs, making repeat testing across a training cycle quick and consistent.
Common Mistakes
- Entering jump height in inches instead of centimeters, which produces a badly inflated power estimate.
- Treating the result as an exact laboratory measurement rather than a regression-based approximation with its own margin of error.
- Comparing raw power estimates between athletes of very different body mass without also considering power output relative to bodyweight.
Edge Cases to Watch For
- The formula is a linear regression fitted to a specific research sample, so its output is a statistical estimate rather than a directly measured power reading from a force plate.
- Very low jump heights combined with low body mass can push the average power equation's result close to its lower range because of the -1393 constant, since the regression was fitted around typical adult athletic values rather than extreme low ends.
- The formula assumes a standard countermovement jump technique measured a specific way; jump height recorded from a different test method, such as a running vertical jump, isn't consistent with what the original formula was validated against.
Common Use Cases
- Strength and conditioning coaches field-testing athlete explosiveness without access to lab equipment.
- Athletes tracking changes in estimated jump power across a training block or off-season.
- Sports scientists and trainers using a quick, published field estimate when force plate testing isn't practical.