How high do you need to jump to dunk? Enter your standing reach and the calculator works out the vertical jump required.
How to use this tool
Stand flat-footed, stretch one arm straight up and mark your fingertips. That is your standing reach — most adults are between 210 and 250 cm.
A regulation rim is 305 cm (10 ft) and a standard men's ball is about 24 cm across. Lower rims or smaller balls need less jump.
The first is the jump to touch the rim; the second adds the ball's diameter, which is roughly what a comfortable dunk needs.
Palm size, timing, approach speed and two-foot vs one-foot jumping all change whether a given vertical is enough on the day.
Formula & worked example
With a 230 cm standing reach, a 305 cm rim and a 24 cm ball: touching the rim needs 75 cm of vertical, and a comfortable dunk needs 75 + 24 = 99 cm.
Limitations — read this before you rely on it
This is a fun estimate, not a biomechanics assessment: it ignores your palm size and grip, how much of the ball must clear the rim for your dunk style, approach speed, and whether you jump off one foot or two. Standing reach measured in shoes on a court will differ slightly from a barefoot wall measurement. Vertical jump training should be progressed gradually to avoid injury.
Frequently asked questions
Roughly rim height minus your standing reach, plus the ball's diameter for a comfortable dunk — for most adults that lands between 60 and 100 cm of vertical.
Touching the rim is not dunking: the ball has to get over the rim and down through the net. Adding the ball's diameter approximates the extra height for the whole ball to clear.
Centimetre for centimetre they are identical — every extra centimetre of reach cuts the required jump by a centimetre. Long arms are free vertical.
Yes, and the calculator shows it: drop the rim height to 275 cm and the same 230 cm reach needs only 45 cm to touch it, or 69 cm comfortably.
It is elite territory — most NBA players are in the 70–100 cm range and most recreational players in the 40–60 cm range. Use the number as a training target, not an expectation.