Dunk Calculator

It depends almost entirely on your standing reach. For a 6'0" player with a typical 96" reach, dunking one-handed needs about a 30-inch vertical. Taller players or those with long arms need far less — a 6'6" player may need only around 22 inches. Enter your numbers above to get your exact figure.

Standing reach is how high you can touch while standing flat-footed with one arm fully extended overhead. Measure it against a wall in socks or bare feet, pushing your shoulder up and reaching as high as possible. It is a better predictor of dunking ability than your height, because arm length and shoulder mobility vary a lot between people of the same height.

No — standing reach matters more than raw height, and reach already bundles in arm length. Two people the same height can have reaches that differ by several inches. A shorter player with long arms and a big vertical can dunk while a taller player with short arms and a small vertical cannot.

For most adults between 5'10" and 6'2", a running vertical in the high-20s to low-30s of inches is the dunking threshold. A 28-inch vertical is roughly NBA-average and is enough for many average-height players with a running approach to throw one down.

A 1–3 step running approach typically adds 3–5 inches of effective vertical over a standing jump. The run-up lets you convert horizontal speed into upward lift through your final plant step, so the approach is genuine extra height, not a measurement trick.

Yes. A 5'10" player with an average reach needs roughly a 29-inch running vertical to dunk one-handed. That is above average but very achievable with focused jump training — plenty of 5'10" recreational athletes dunk.

Hang time is the total time your feet are off the floor during a jump. It comes from projectile motion: once you leave the ground, you are in free fall. Hang time equals 2 × √(2h ÷ g), where h is your jump height in meters and g is gravity (9.81 m/s²). A 30-inch vertical produces roughly 0.78 seconds of hang time.

Most untrained adults can add 10–15 inches over 3–6 months with structured training: heavy strength work (squats, deadlifts), explosive plyometrics (depth jumps, bounds), and technique work on a one- or two-step approach. Consistency and progressive overload matter more than any single drill.

Your vertical is the highest point you can touch minus your standing reach. A regulation rim is 120 inches (305 cm), so if you can just touch the rim and your standing reach is 90 inches, your vertical is 120 − 90 = 30 inches. Enter your touch height in the "Highest Point You Can Touch" field above and the calculator does this for you. Because a measured touch already includes your run-up, no approach bonus is added on top.

On a regulation goal the bottom edge of the backboard sits at 9 feet (108 inches), a full 12 inches below the rim. So touching the backboard needs 12 inches less vertical than touching the rim, and 18 inches less than a one-hand dunk. For a player with a 90-inch standing reach that is an 18-inch vertical for the backboard versus a 36-inch vertical to dunk.

Yes. Set the Units field to "Centimetres (cm)", enter your height in the Height (cm) box, and give every other length — standing reach, wingspan, touch height, vertical jump — in centimetres too. Results come back in centimetres. A regulation rim is 305 cm, and the calculator accepts rim heights entered in centimetres as well.

Lowering the rim lowers the target one-for-one. A 9-foot rim needs 12 inches less vertical than a 10-foot rim; an 8-foot rim needs 24 inches less. A 5'6" player with an estimated 87.8-inch reach needs roughly a 38-inch vertical to dunk on a regulation rim, about 26 inches on a 9-foot rim, and about 14 inches on an 8-foot rim. Change the Rim Height field to match the hoop you are actually on.

Some can, usually on a lowered rim. Youth leagues commonly play on 8-foot or 9-foot goals, and dunking on those needs 24 or 12 inches less vertical than a regulation rim. On a full 10-foot rim it is rare before a growth spurt, because required vertical falls as standing reach rises. Set your real rim height above to get an honest number, and note that heavy jump training is best introduced under a qualified coach while you are still growing.

Standing reach tracks wingspan more closely than height. If you know your wingspan but have never measured your reach, enter it in the Wingspan field and the calculator adjusts the height-based estimate by half of the difference between your wingspan and your height. A measured reach is always better — it takes thirty seconds against a wall and removes the biggest source of error in the whole calculation.