The Jump Power Calculator is a free online tool that works in your browser. There is nothing to install, no account to create, and no data sent anywhere. You enter a few numbers, press calculate, and get a clear result you can use in your next training session.
What it measures
Jump height is a quick, honest measure of lower-body power. You jump as high as you can, and the height you reach, combined with your body weight, lets coaches estimate the peak power your legs produced. This calculator uses the Sayers equation, a widely used formula in sports science, to turn a simple jump measurement into watts and watts per kilogram, with no force plate or lab visit needed.
How to use it
Fill in each field with your own numbers, then press Calculate. Use honest measurements: a guessed input gives a guessed result. If a field does not apply to you, use the closest value and note it, so your next test uses the same setup and the comparison stays fair. Results appear below the button at once, and you can change any input and recalculate as often as you like.
Who should use it
This tool suits athletes, coaches, and anyone who trains regularly and wants numbers to guide sessions. Beginners get a starting point and a first target. Experienced athletes get a consistent way to track change over a season. Coaches can test a whole group with the same method and compare results fairly, as long as everyone follows the same test conditions.
How to read your result
Peak power in watts is the headline number: higher means more explosive legs. Relative power in watts per kilogram is the fairer comparison, because a heavier athlete must move more mass to reach the same height. If your relative power climbs over a training block while your jump height also rises, your power training is working. If jump height rises but relative power does not, check whether body weight changed at the same time.
Worked example
Take an 80 kg athlete who jumps 50 cm. The calculator estimates about 4604 watts of peak power, or roughly 57.6 watts per kilogram. A 60 cm jump at the same weight would push the estimate above 5200 watts. That is why ten extra centimetres matter so much: power rises fast with height, and even small gains from plyometric training show up clearly in the numbers.
How to use it in training
Measure jump height with a wall mark or a phone app, and take the best of three honest jumps. Warm up with light jumps first; a cold maximal jump risks a strain and understates your power. Add two plyometric sessions a week, with box jumps and squat jumps, and retest monthly. Keep a simple log of each test date and result. Over eight to twelve weeks, the trend matters far more than any single day, because sleep, heat, and fatigue move daily numbers up and down.
Accuracy and limits
Every estimate on this page is educational, not medical advice. Field formulas trade lab precision for simplicity, so treat results as guides for training, not diagnoses. If you have a heart condition, feel unwell during exercise, or get a result that worries you, stop and talk to a qualified professional before training hard again. Consistent test conditions matter more than chasing a perfect number.
Frequently asked questions
How often should I retest? Every four to eight weeks is enough for most training blocks. Shorter gaps mostly show daily noise, not real change.
Do I need special equipment? Most of these tests need only a timer, a tape measure, or a basic heart rate monitor. A lab gives more precision, but a careful field test is enough to guide training.
Also available in Spanish: Calculadora de Potencia de Salto.