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Vertical Jump Power Calculator

Estimates lower-body power from a vertical jump height and body mass with the Sayers peak-power equation (60.7·height + 45.3·mass − 2055), the Harman peak-power equation and the Lewis average-power formula, plus take-off velocity and flight time.

When to use

You have a measured vertical jump (jump-and-reach or countermovement jump height) and body mass and want an estimate of peak or average muscular power in watts.

Do not use when: Force-plate power data are available (they measure power directly), or you need strength rather than power (use one-rep-max).

Formula

Sayers: P_peak = 60.7·h_cm + 45.3·m_kg − 2055; Harman: P_peak = 61.9·h_cm + 36.0·m_kg − 1822; Lewis: P_avg = √4.9 × m_kg × √(h_cm/100) × 9.81; v_takeoff = √(2·g·h); t_flight = 2·v_takeoff / g

Sayers et al. (1999) derived the equation on 108 college athletes and non-athletes from squat-jump heights against force-plate peak power (SEE ≈ 355 W) and found separate equations for men and women unnecessary; applied to countermovement-jump heights it over-estimates by about 2.7 %. Harman (1991) and Lewis are older estimates included for comparison.

Inputs

Parameter	Type	Unit	Required	Description
`jump_height_cm`	number	cm	yes	Vertical jump height: jump-and-reach difference or countermovement-jump rise of the centre of mass. Range: ≥ 10, ≤ 150
`body_mass_kg`	number	kg	yes	Body mass in kilograms (the equations were fitted to adults). Range: ≥ 30, ≤ 300

Outputs

Output	Type	Unit	Description
`sayers_peak_power_w`	number	W	60.7 × jump_height_cm + 45.3 × body_mass_kg − 2055 (recommended equation).
`harman_peak_power_w`	number	W	61.9 × jump_height_cm + 36.0 × body_mass_kg − 1822.
`lewis_average_power_w`	number	W	√4.9 × body_mass_kg × √(jump_height_m) × 9.81; underestimates true power and is kept for comparison with older norms.
`relative_peak_power_w_per_kg`	number	W/kg	Sayers peak power divided by body mass.
`takeoff_velocity_m_per_s`	number	m/s	√(2 × g × height) with g = 9.80665 m/s².
`flight_time_s`	number	s	2 × takeoff_velocity / g (symmetric flight).

Example

50 cm jump, 75 kg: {"jump_height_cm":50,"body_mass_kg":75} → {"sayers_peak_power_w":4378,"harman_peak_power_w":3973,"lewis_average_power_w":1152,"relative_peak_power_w_per_kg":58.37,"takeoff_velocity_m_per_s":3.13,"flight_time_s":0.639}

30 cm jump, 60 kg: {"jump_height_cm":30,"body_mass_kg":60} → {"sayers_peak_power_w":2484,"harman_peak_power_w":2195,"lewis_average_power_w":714,"relative_peak_power_w_per_kg":41.4,"takeoff_velocity_m_per_s":2.43,"flight_time_s":0.495}

GET https://tttkmbb.com/api/v1/calculate/vertical-jump-power?jump_height_cm=50&body_mass_kg=75

Machine access

API: GET https://tttkmbb.com/api/v1/calculate/vertical-jump-power (query parameters) or POST with a JSON body {"inputs": {...}}
Schema: https://tttkmbb.com/api/v1/calculators/vertical-jump-power · Markdown: https://tttkmbb.com/fitness/vertical-jump-power.md · JSON definition: https://tttkmbb.com/fitness/vertical-jump-power.json
MCP: server https://tttkmbb.com/mcp, tool run_calculator with calculator_id="vertical-jump-power"
OpenAPI operationId: estimate_vertical_jump_power
Freshness: static. Authentication: none. Rate limit: fair use (see rate limits).

Sources

FAQ

Why is the Lewis value so much lower?

The Lewis nomogram estimates average power during the push-off and ignores body-mass displacement before take-off; Sayers found it under-estimates force-plate peak power by roughly 70 %. Use Sayers for peak power.

Which jump height should I enter?

Jump-and-reach (standing reach subtracted) or a countermovement jump measured by a mat or app. Heights from arm-swing jumps are higher and inflate the estimate.

Related calculators

One-Rep Max Calculator — Maximal strength estimate for the same athlete.
Free Fall Calculator — Flight time and velocity for any drop or rise height.
Kinetic Energy Calculator — Energy at take-off from mass and velocity.