Dunk Calculator
Estimate the vertical jump needed to dunk a basketball from your standing reach, rim height, and desired clearance. Enter your standing reach, rim height, and clearance target to see how close you are to a regulation dunk.
Basketball Dunking Tips
Dunking a basketball depends mainly on how high your hand can reach at the top of your jump. Enter your measured standing reach, the rim height, and the amount of clearance you want above the rim. The calculator then estimates the vertical jump needed to reach that target. A one-handed practice dunk may require less clearance than a controlled two-handed dunk in a game.
Quick Guide
- Measure standing reach barefoot or in basketball shoes with one arm fully extended.
- Use 120 inches for a regulation 10-foot basketball rim.
- Add about 4 to 6 inches of clearance for a cleaner, more controllable dunk attempt.
- Compare the required jump with your tested vertical to set a realistic training target.
Required Vertical Jump
Find how many inches you must jump above your standing reach to reach the rim plus your chosen clearance.
One-Hand vs Two-Hand Dunks
Test lower clearance for a basic one-hand dunk and more clearance for stronger ball control or two hands.
Set a Training Target
Compare the required vertical with your current jump to see how many inches of improvement you need.
Required Vertical Jump To Dunk Formula and Inputs
Required vertical = target reach - standing reach.
The dunk is most useful when the inputs all describe the same context. Avoid mixing full-season stats with one-game values unless that is the comparison you intentionally want to make.
| Input | How to Use It |
|---|---|
| Standing reach | Enter the value from the same game, season, round, workout, or scenario you are analyzing. |
| Rim height | Enter the value from the same game, season, round, workout, or scenario you are analyzing. |
| Desired clearance | Enter the value from the same game, season, round, workout, or scenario you are analyzing. |
Specialized Calculator Tools
These closely related calculators are available on our topic-focused websites.
How High Do You Need to Jump to Dunk?
The jump required to dunk is the difference between your standing reach and the height your hand must reach while airborne. A regulation basketball rim is 10 feet, or 120 inches, above the floor. Merely touching 120 inches may let you grab the rim, but controlling the ball above it requires additional clearance.
For a basic one-handed dunk in practice, many players begin by testing about 4 to 6 inches of clearance. Two-handed dunks, powerful finishes, alley-oops, and dunks in traffic usually demand more height because the ball must remain controlled while both hands or the full ball clear the rim.
Dunk Calculator Formula
Vertical jump needed = rim height + desired clearance − standing reach
Example: a player with a 96-inch standing reach who wants 6 inches of clearance above a 120-inch rim needs a 30-inch vertical jump: 120 + 6 − 96 = 30 inches.
Estimated Vertical Jump Needed by Standing Reach
The chart below assumes a regulation 120-inch rim and 6 inches of hand clearance. Your actual requirement may differ with hand size, approach technique, ball control, and the type of dunk.
| Standing Reach | Vertical Needed to Touch Rim | Vertical Needed With 6-Inch Clearance |
|---|---|---|
| 84 in (7 ft 0 in) | 36 in | 42 in |
| 88 in (7 ft 4 in) | 32 in | 38 in |
| 92 in (7 ft 8 in) | 28 in | 34 in |
| 96 in (8 ft 0 in) | 24 in | 30 in |
| 100 in (8 ft 4 in) | 20 in | 26 in |
| 104 in (8 ft 8 in) | 16 in | 22 in |
How to Measure Your Standing Reach
Stand flat-footed beside a wall with the shoulder closest to the wall relaxed. Reach as high as possible with one arm without rising onto your toes or leaning dramatically. Mark the highest point reached by the fingertips and measure from the floor to that mark. Basketball shoes can add a small amount, so measure in the footwear you normally use when you want a game-specific estimate.
Improving Your Chances of Dunking
A larger vertical jump helps, but technique matters too. Practice a consistent penultimate step, convert approach speed into upward force, swing the arms aggressively, and learn whether a one-foot or two-foot takeoff suits you better. Strength work for the hips and legs, controlled plyometrics, sprinting, adequate recovery, and gradual jump practice can all support improvement.
Increase training volume gradually. Repeated maximal jumps can stress the knees, ankles, and Achilles tendons, especially when fatigue changes landing mechanics. Quality attempts with full recovery are generally more useful than endless tired jumps.