Vertical Jump Height Calculator
This calculator measures vertical jump height using two methods. The hang time method uses projectile motion physics: jump height in metres equals gravitational acceleration (9.81 m/s squared) multiplied by total air time squared, divided by 8. The reach test (Sargent jump) method subtracts your standing reach from your maximum jump reach, giving vertical displacement directly in inches. Select your preferred method, enter the required measurements, and the calculator returns jump height in both inches and centimetres. For the reach test, you can optionally enter body weight in pounds to calculate estimated peak power output using the Lewis formula, a standard NSCA testing tool. A benchmark table compares your result against average adults, college athletes, NBA combine averages, and elite performers including Zion Williamson's recorded test result.
Vertical jump height: -- inches (-- cm)
How jump height is calculated
Hang time method:
h (metres) = g x t^2 / 8
g = 9.81 m/s^2, t = total air time (seconds)
Reach test method:
Jump height (inches) = Jump reach (in) - Standing reach (in)
Lewis formula (power output):
Power (W) = sqrt(4.9) x weight (kg) x sqrt(height in metres) x 9.81
Worked examples
Hang time method: hang time = 0.65 seconds:
- h = 9.81 x (0.65)^2 / 8 = 9.81 x 0.4225 / 8 = 0.518 m = 51.8 cm = 20.4 inches
Reach test: standing reach 90 inches, jump reach 114 inches, weight 180 lbs (81.65 kg):
- Jump height = 114 - 90 = 24 inches = 60.96 cm = 0.610 m
- Power = sqrt(4.9) x 81.65 x sqrt(0.610) x 9.81 = 2.214 x 81.65 x 0.781 x 9.81 = 1,384 watts
Vertical jump benchmarks
| Group | Jump height (inches) | Jump height (cm) |
|---|---|---|
| Average adult male | 16 to 20 | 41 to 51 |
| Average adult female | 12 to 16 | 30 to 41 |
| College athlete (average) | 24 to 28 | 61 to 71 |
| NBA combine average | 28 | 71 |
| Elite (NBA, volleyball) | 32 to 40 | 81 to 102 |
| Zion Williamson (tested) | 45 | 114 |
NBA combine and athlete benchmarks are sourced from NSCA published testing data. Individual results vary by testing protocol and conditions.
Which method should I use?
The reach test (Sargent jump) is recommended for most people because it directly measures the actual height you cleared, without requiring specialist timing equipment. You need: a wall, chalk or tape, and a helper to mark the highest point.
The hang time method is useful if you have a jump mat or can record your jump with high-speed video (slow-motion camera on most modern smartphones). Measure time from the last contact with the ground to the first contact on landing. Small errors in hang time measurement create significant errors in jump height (0.01 second timing error at 0.6 seconds of hang time equals approximately 1.5 cm error), so accuracy matters.
For NSCA-standard testing, the reach test is the default protocol because it is most reproducible without a laboratory setup.
Jump height calculator: frequently asked questions
How does the hang time method calculate jump height?
The hang time method uses the physics of projectile motion. When you jump and leave the ground, you are in free fall under gravity. The formula is: h = g x t^2 / 8, where h is jump height in metres, g is gravitational acceleration (9.81 m/s^2), and t is total hang time (from takeoff to landing) in seconds. Dividing by 8 (not 2) accounts for the fact that hang time includes both the ascent and descent. This method requires accurate hang time measurement, which is best done with a jump mat or high-speed video.
How does the reach test method work?
The reach test (also called the Sargent jump test) measures vertical jump as the difference between your maximum jump reach and your standing reach. Stand flat-footed next to a wall and mark the highest point you can touch (standing reach). Then jump and mark the highest point touched. The difference between the two marks is your vertical jump height. This is the most practical method for measuring vertical jump without specialist equipment.
What is the Lewis formula for power output?
The Lewis formula estimates peak power output from a vertical jump test. The formula used in this calculator is: Power (watts) = sqrt(4.9) x body weight (kg) x sqrt(jump height in metres) x 9.81. The Lewis formula was developed for use with the vertical jump test and is a standard tool in the National Strength and Conditioning Association's testing protocols. It provides a practical estimate of explosive leg power without a force plate.
What is a good vertical jump height?
Average vertical jump height for adult males is 16 to 20 inches (40 to 51 cm); for adult females, 12 to 16 inches (30 to 41 cm). NBA combine participants average approximately 28 inches (71 cm). Elite athletes in jumping sports (basketball, volleyball, high jump) often exceed 30 to 36 inches. Zion Williamson was recorded at 45 inches (114 cm) during testing. These benchmarks come from published combine and testing data sourced from the National Strength and Conditioning Association.
How can I improve my vertical jump?
Vertical jump height is primarily determined by lower-body explosive strength and power. Effective training methods include: depth jumps and plyometrics (neuromuscular power), heavy squats and Romanian deadlifts (max strength), Olympic lifting variations (rate of force development), and sprint training (hip extension power). The National Strength and Conditioning Association recommends a periodised approach combining max strength phases with explosive power phases for maximum improvement.
Official sources
- National Strength and Conditioning Association (NSCA): nsca.com. NSCA's Essentials of Strength Training and Conditioning.
- Lewis, D.A. (1974). Physical fitness tests. Published protocols referenced in NSCA testing guidelines.
Reviewed by the CalculatorHub team, edited by James Graham, 14 June 2026. See our methodology. General information only.