Strength calculator
Vertical jump power calculator
Turn a vertical jump into watts — peak and average anaerobic power from the Sayers equations. Free, instant, no sign-up.
Power is trainable — the coach can put jumps, throws, and heavy singles where they belong in your week.
What does a vertical jump measure?
A vertical jump is the cheapest lower-body power test that exists: how high you leave the ground is a direct readout of how much force you can produce and how fast you can produce it. Jump height on its own only ranks you against people of the same size, though. Converting it to watts folds body mass back in, which is what lets you compare a 60 kg jumper with a 100 kg one and what makes the number worth tracking as you gain or lose weight.
How this calculator works
The headline figure is the Sayers peak power equation — 60.7 × jump height in cm + 45.3 × body mass in kg − 2055 — published by Sayers and colleagues in Medicine & Science in Sports & Exercise in 1999, where three jump-power equations were cross-validated against force-plate measurements in 108 athletes. The same paper gives a countermovement variant (51.9 × height + 48.9 × mass − 2007) for jumps that start with a dip, and the average-power figure comes from Harman and colleagues (1991). All three are regressions fitted on healthy athletic populations, so they return nothing useful for very light jumpers with very small jumps.
Measuring the jump properly
Use the same method every time and never mix them: a Vertec or wall-touch measures reach-to-touch displacement, a contact mat infers height from flight time, and the two disagree by several centimetres on the same athlete. Warm up thoroughly, take three attempts with full rest between them, and keep the record of your best. For the squat-jump equation, start from a held quarter-squat with no dip; for the countermovement figure, jump the way you would naturally, with arms swinging or not — but pick one and stay with it.
Using the number
Peak power in watts is what you compare against teammates and published norms; watts per kilogram is what you compare against yourself over a season, because it strips out weight change. If absolute power climbs while relative power sits flat, the gain came from mass, not from getting more explosive. The most common cause of a stalled jump in a lifter who is otherwise progressing is simple: the training has plenty of heavy slow work and nothing fast in it.