Dunk Calculator
Find out exactly how high you need to jump to dunk a basketball. Enter your height, wingspan or standing reach and current vertical, and see your jump play out against the rim in real time.
Built and reviewed by Manzoor Khan, 13+ years in web development and SEO, pharmacist with 9+ years writing about sports nutrition. Updated October 2, 2026.
Uses the regulation 10 ft (3.05 m) rim from NBA, NCAA and FIBA rules, projectile physics for hang time, and the Sayers equation for jump power.
Your measurements
Results update as you type. Only height is required.
Reach is estimated as height × 1.33 when you don’t enter it, adjusted by half of any wingspan difference.
Your dunk ladder
Every common dunk, the extra height your fingertips need above the rim, and the vertical it takes for you.
| Dunk | Above rim | Vertical needed | Your status |
|---|
Training outlook
A realistic read on closing the gap, plus jump power from the Sayers equation.
Add your verticalEnter your current vertical jump to see how far you are from the rim and roughly how long a structured program could take.
Add your body weight to estimate the peak power your dunk demands.
How high do you need to jump to dunk?
To dunk on a regulation 10-foot rim, your vertical jump must equal 120 inches plus about 6 inches of clearance, minus your standing reach. An average 5’10” adult with a 7’9″ standing reach needs roughly a 33-inch running vertical to dunk and about 27 inches just to touch the rim.
Key takeaways
- Formula: vertical needed to dunk = 120 in rim + about 6 in clearance − standing reach.
- Standing reach averages about 1.33 × height, and long arms lower the jump you need.
- At 6’0″ with average arms you need roughly a 30-inch running vertical; at 5’9″ about 34 inches.
- Grabbing rim usually means you are about 3 to 4 inches from a one-hand dunk.
- Realistic progress is about 0.5 to 1 inch of vertical per month with structured strength and plyometric training.
The dunk calculator above works this out for your body, not an average one. Standing reach drives the result far more than height alone, because two players of the same height can differ in reach by several inches through arm length and shoulder width. That’s why the calculator asks for wingspan and lets you enter a measured reach directly.
How the dunk calculator works: the formula
Vertical needed = Rim height + Dunk clearance − Standing reach
Rim height is 120 in (305 cm) on a regulation hoop. Clearance is how far your fingertips must rise above the rim for the dunk you want.
Each input feeds that one equation, and the extra outputs come from basic physics:
- Standing reach. If you leave it blank, the calculator estimates it as height × 1.33, a widely used anthropometric rule. When you add wingspan, it adds half of the wingspan-minus-height difference, since only one arm reaches up.
- Dunk clearance. A rim touch needs zero. A one-hand dunk needs about 6 inches so the ball clears the front of the rim, and showier dunks need more. If you can’t palm the ball, the calculator adds 2 inches because you have to carry the ball higher with a cupped wrist or two hands.
- Run-up versus standing. A running approach usually adds several inches to a standing vertical. When you enter only one, the calculator converts with a 1.2 ratio and labels it as an estimate.
- Takeoff speed and hang time. The speed needed to reach a given height is √(2 × g × h). The time your hand spends above the dunk line comes from the same projectile equation, which shows why a few spare inches make dunking feel much easier.
- Peak power. If you add body weight, the calculator applies the Sayers equation (Peak power in watts = 60.7 × jump height in cm + 45.3 × body mass in kg − 2,055), using a standing-jump equivalent because that’s how the equation was built.
Worked example: can a 5’10” player dunk?
Take a 5’10” (70 in) player with a 72-inch wingspan and a 26-inch running vertical, aiming for a one-hand dunk on a 10-foot rim.
- Estimated standing reach: 70 × 1.33 = 93.1 in, plus half the 2-inch wingspan surplus, gives 94.1 in (about 7’10”).
- Vertical to touch the rim: 120 − 94.1 = 25.9 in.
- Vertical to dunk with one hand: 120 + 6 − 94.1 = 31.9 in.
- Gap: 31.9 − 26 = 5.9 in short. This player can touch rim today and is a focused training block or two away from a one-hand dunk.
Vertical needed to dunk by height: 5’4″ to 6’6″
Most people searching “can I dunk at 5’9″?” or “how much vertical do I need to dunk at 6’2″?” fall in this range, so the chart goes inch by inch. It uses the height × 1.33 reach estimate, a 6-inch one-hand dunk clearance and average arm length. Find your height, then run the calculator with your wingspan for a personal number.
| Height | Dunk, 10 ft rim | Touch rim | Dunk, 9 ft rim | Est. standing reach |
|---|---|---|---|---|
| 5’4″ (163 cm) | 40.9 in | 34.9 in | 28.9 in | 7’1.1″ (216 cm) |
| 5’5″ (165 cm) | 39.5 in | 33.5 in | 27.5 in | 7’2.5″ (220 cm) |
| 5’6″ (168 cm) | 38.2 in | 32.2 in | 26.2 in | 7’3.8″ (223 cm) |
| 5’7″ (170 cm) | 36.9 in | 30.9 in | 24.9 in | 7’5.1″ (226 cm) |
| 5’8″ (173 cm) | 35.6 in | 29.6 in | 23.6 in | 7’6.4″ (230 cm) |
| 5’9″ (175 cm) | 34.2 in | 28.2 in | 22.2 in | 7’7.8″ (233 cm) |
| 5’10” (178 cm) | 32.9 in | 26.9 in | 20.9 in | 7’9.1″ (236 cm) |
| 5’11” (180 cm) | 31.6 in | 25.6 in | 19.6 in | 7’10.4″ (240 cm) |
| 6’0″ (183 cm) | 30.2 in | 24.2 in | 18.2 in | 7’11.8″ (243 cm) |
| 6’1″ (185 cm) | 28.9 in | 22.9 in | 16.9 in | 8’1.1″ (247 cm) |
| 6’2″ (188 cm) | 27.6 in | 21.6 in | 15.6 in | 8’2.4″ (250 cm) |
| 6’3″ (190 cm) | 26.2 in | 20.2 in | 14.2 in | 8’3.8″ (253 cm) |
| 6’4″ (193 cm) | 24.9 in | 18.9 in | 12.9 in | 8’5.1″ (257 cm) |
| 6’5″ (196 cm) | 23.6 in | 17.6 in | 11.6 in | 8’6.4″ (260 cm) |
| 6’6″ (198 cm) | 22.3 in | 16.3 in | 10.3 in | 8’7.7″ (263 cm) |
Values are running-vertical targets for a one-hand dunk. On small screens, swipe sideways to see estimated reach.
Three patterns stand out. Every extra inch of height lowers the vertical you need by about 1.3 inches, because reach grows faster than height. A 5’9″ player needs roughly a 34-inch running vertical, which is achievable for trained athletes. And at 5’6″ or shorter, a one-hand dunk on a regulation rim takes a vertical of about 38 inches or more. That is rare, but it has been done by players like Spud Webb and three-time NBA Slam Dunk champion Nate Robinson, listed at 5’9″.
Average standing reach by height
Standing reach is the height your fingertips reach with one arm fully raised while you stand flat-footed. For most adults it falls between about 1.30 and 1.36 times height, which is why 1.33 is the standard estimate used by dunk calculators and coaches. A 6’0″ person averages about 7’11.8″ and a 5’6″ person about 7’3.8″.
Your personal ratio depends mainly on arm length and shoulder width. Your ape index, wingspan minus height, is the best quick check. A positive ape index pushes your reach above the 1.33 average, and each inch of extra wingspan adds roughly half an inch of reach, since only one arm goes up. Basketball players, especially at the NBA Draft Combine, tend to sit at the long-armed end of the range, which is part of why they dunk so easily.
Can I dunk? The rim milestones that show how close you are
Most players climb the same ladder on the way to their first dunk. Where you sit today tells you a lot about your gap, even before you measure your vertical.
- Touch the net. Roughly 12 to 18 inches below the rim. A solid starting point.
- Touch the backboard square or rim. Your fingertips reach 10 feet. You are about 6 inches from a one-hand dunk.
- Grab the rim. Your fingers wrap the rim, putting your fingertips about 2 to 3 inches above it. You are about 3 to 4 inches away.
- Dunk a tennis ball or volleyball. Proves your clearance and timing. Smaller balls need less height and grip.
- Rim grazer. A dunk where the ball barely clears and your hand scrapes the rim. It counts, and it means you are at the line.
- Clean one-hand dunk, then two-hand. Clearing the rim by 6 inches or more makes the dunk reliable in games.
One-foot or two-foot takeoff?
One-foot jumpers usually convert speed into height better and reach higher off a long run-up. Two-foot jumpers tend to be stronger and more stable in traffic. Test both with your measured vertical and dunk off whichever gives you the higher touch.
Does body weight matter?
Yes. In the Sayers equation, every extra kilogram adds about 45 watts to the power needed for the same jump height. Losing fat while keeping strength raises your vertical without any extra power, which is why coaches say “fat doesn’t fly.”
Can women dunk?
Yes. Women’s college and professional basketball use the same 10-foot rim with a slightly smaller size 6 ball. Georgeann Wells became the first woman to dunk in an NCAA game in 1984, and Lisa Leslie threw down the first WNBA dunk in 2002. Because average standing reach is lower, most women need a larger vertical to dunk. A 5’4″ player with average arms needs about a 41-inch running vertical for a one-hand dunk, while a 6’2″ player needs about 28 inches. The calculator works the same for everyone, so enter your own height, wingspan and reach for an accurate target.
How to measure standing reach and vertical jump at home
Your result is only as good as your measurements. A one-inch error in reach shifts the required vertical by the same inch, so take five minutes to measure properly.
- Standing reach. Stand side-on to a wall in bare feet, flat-footed. Raise the arm closest to the wall straight up, without shrugging or rising onto your toes, and mark the highest fingertip point. Measure from the floor to the mark.
- Standing vertical. Chalk your fingertips, stand side-on to the wall, dip and jump straight up, touching as high as you can. Subtract standing reach from the highest mark. Take the best of three attempts.
- Running vertical. Repeat with a 2–3 step approach and a one- or two-foot takeoff, whichever you’d dunk with. This is the number most comparable to an in-game dunk attempt.
- Wingspan. Stand with your back to a wall, arms stretched straight out at shoulder height, and measure fingertip to fingertip.
How tall do you have to be to dunk?
There’s no minimum height. Dunking is a reach-plus-jump problem, and height is just one part of reach. A 6’0″ player with average proportions needs about a 30-inch running vertical, which many trained athletes reach. At 5’6″, the requirement climbs to around 38 inches. Spud Webb, listed at 5’7″, won the 1986 NBA Slam Dunk Contest, and shorter players with long arms and strong approach jumps still dunk in rec leagues and high school gyms.
If the calculator shows a large gap, two levers matter most: a longer reach you can’t change, and a vertical you can. Long-armed players should enter their wingspan, since an extra 3 inches of wingspan adds about 1.5 inches of reach and cuts the jump needed by the same amount.
How to close the gap and dunk sooner
Vertical jump improves through a mix of strength, rate of force development, technique and body composition. A meta-analysis by Markovic (2007, British Journal of Sports Medicine) found plyometric training improved countermovement jump height by roughly 8.7% on average. For a 26-inch jumper, that’s about 2 inches from one well-run block, which is why the calculator’s training outlook gives a range in months rather than weeks.
- Gap of 0 to 3 inches. Technique first. Sharpen the penultimate step, use a full arm swing, and practise your takeoff foot. Many players find these inches without getting any stronger.
- Gap of 3 to 8 inches. Combine two lower-body strength sessions a week (squats, trap-bar deadlifts, split squats) with low-volume plyometrics like depth jumps, box jumps and bounds.
- Gap of more than 8 inches. Build a strength base for several months, look at body composition, since extra weight raises the power you need, and practise finishing on an adjustable 9-foot rim while you train.
Dunk calculator FAQs
On a regulation 10-foot rim, you need a vertical equal to 120 inches plus about 6 inches of clearance, minus your standing reach. An average 5'10" adult with a 7'9" standing reach needs roughly a 33-inch running vertical to dunk and about 27 inches to touch the rim.
There is no minimum height. A 6'0" player with average proportions needs about a 30-inch running vertical, while a 5'6" player needs around 38 inches. Spud Webb, listed at 5'7", won the 1986 NBA Slam Dunk Contest, so reach and jumping ability matter more than height alone.
Standing reach is the height your fingertips reach when you stand flat-footed and stretch one arm straight up. Stand side-on to a wall in bare feet, raise the near arm without rising onto your toes, mark the highest point and measure from the floor. It is the single most important input in a dunk calculator.
The formula is exact for the numbers you enter. Accuracy depends on your inputs: a measured standing reach is accurate to within an inch, while the height-based estimate can be off by 2 to 3 inches for people with unusually long or short arms. Dunk clearances are practical estimates, so treat results as a planning guide.
Yes. A running approach lets you convert horizontal speed into lift, so most players jump several inches higher with a run-up. This calculator converts between the two with a 1.2 ratio when you only know one, and labels that conversion as an estimate.
Yes. Only one arm reaches up, so each extra inch of wingspan over your height adds about half an inch to your standing reach and cuts the vertical you need by the same amount. A player with a +4 inch wingspan needs about 2 inches less jump than someone the same height with an even wingspan.
Yes, but you usually need more height. Without a palm grip you have to cup the ball against your wrist or use two hands, which means carrying it higher over the rim. The calculator adds about 2 inches of clearance when you select that you cannot palm the ball.
It depends on your gap and training history. Research reviews of plyometric training show average countermovement jump gains of roughly 5 to 9 percent over a training block, which works out to about 1 to 3 inches for many players. A realistic pace is around half an inch to an inch per month with consistent strength and jump training.
At the NBA Draft Combine, maximum running verticals typically land in the mid-30s in inches, with standing verticals several inches lower. Because NBA players also have long standing reaches, many of them need far less than that to dunk.
Yes. Many coaches use adjustable 8 to 9 foot rims to build confidence, ball control and finishing technique while vertical jump training continues. Choose a lower rim height in the calculator to see exactly how much jump each rim requires.
Yes. With average arm length, a 5'9" player has a standing reach of about 7'7.8" and needs roughly a 28-inch vertical to touch the rim and a 34-inch running vertical for a one-hand dunk. A longer wingspan, a strong approach and focused jump training make it realistic. Nate Robinson, listed at 5'9", won the NBA Slam Dunk Contest three times.
A regulation basketball rim is 10 feet (120 inches) high, which is 3.05 meters or about 305 centimeters, measured from the floor to the top of the rim. The NBA, WNBA, NCAA, high school and FIBA all use this height. Youth leagues often use 8 to 9 foot rims.
Usually about 3 to 4 inches. Grabbing the rim puts your fingertips roughly 2 to 3 inches above it, while a clean one-hand dunk needs about 6 inches of clearance. Players at this stage often finish their first dunk by improving approach technique and adding a little lower-body strength.
A rim grazer is a dunk where the ball only just clears the rim and the hand scrapes it on the way down. It counts as a dunk and shows you have reached the dunk line. Adding 2 to 3 more inches of vertical turns it into a clean, repeatable dunk.
Yes. Women's basketball uses the same 10-foot rim with a slightly smaller size 6 ball. Georgeann Wells recorded the first dunk in an NCAA women's game in 1984, and Lisa Leslie made the first WNBA dunk in 2002. Because average standing reach is lower, most women need a larger vertical, which the calculator shows for any height.
Yes. Switch the units toggle to centimeters to enter height, wingspan, standing reach and vertical in centimeters and body weight in kilograms. Your existing entries convert automatically and all results display in metric.
Methodology and sources
Rim height follows the 10 ft (3.05 m) standard in NBA, NCAA and FIBA rules. Standing reach uses the height × 1.33 rule with a half-wingspan adjustment. Dunk clearances are practical estimates drawn from ball size and common coaching guidance, not official measurements. Run-up conversion uses a 1.2 ratio. Physics uses g = 9.81 m/s². Peak power uses Sayers et al. (1999, Medicine & Science in Sports & Exercise). Training ranges reference Markovic (2007, British Journal of Sports Medicine).
This dunk calculator is for education and training planning. Results are estimates. Jumping and landing carry injury risk, so build volume gradually and get clearance from a qualified professional if you have joint, back or heart problems.