Dunking takes reaching a few inches above the rim with the ball in hand. Your standing reach – how high you can touch flat-footed – and the hoop height decide how much vertical leap you need.
How to use the Dunk Calculator
- Hoop
- Hoop height
- Body mass
- Standing reach
- Ball clearance above the rim
Results update as you type, every field has its own unit menu, and everything is calculated in your browser.
How it works
Choose the hoop (or enter its height), enter your body mass, standing reach and the extra height needed to get the ball over the rim (about 15 cm / 6 in with a palm grip).
Tips
- Use totals, not per-game averages, for percentages.
- Advanced stats like eFG% and TS% credit three-pointers and free throws properly.
- Compare a player’s numbers with league averages.
- Everything runs in your browser.
Common mistakes to avoid
- Counting free throws as field goals.
- Mixing per-game and season totals.
- Judging shooters from very few attempts.
Inputs explained
| Field | What to enter |
|---|---|
| Hoop | Choose one: Standard 10 ft (3.05 m), 9 ft (grades 5–6), 8 ft (grades 3–4), 7 ft (grade 2 and under) … |
| Hoop height | Units: ft, m, in, yd, cm |
| Body mass | Units: kg, lb |
| Standing reach | Units: ft, cm, in, m |
| Ball clearance above the rim | Units: in, cm |
What each result means
- Minimum vertical leap = max(0, [H] – [Standing reach] + [Ball clearance above the rim])
- Jumping energy = [Body mass]×9.80665×max(0, [H] – [Standing reach] + [Ball clearance above the rim])
- Take-off speed = sqrt(2×9.80665×max(0, [H] – [Standing reach] + [Ball clearance above the rim]))
- Hang time = sqrt(8×max(0, [H] – [Standing reach] + [Ball clearance above the rim])÷9.80665)
Example values
How the main result changes when Hoop height changes and everything else stays at the example values above:
| Hoop height (ft) | Minimum vertical leap (in) |
|---|---|
| 5 | 30 |
| 7.5 | 30 |
| 10 | 30 |
| 12.5 | 30 |
| 15 | 30 |
| 20 | 30 |
Formula
Vertical leap = hoop height − standing reach + clearance, E = m·g·h, v = √(2gh), hang time = √(8h/g)
Worked example
Inputs — Hoop: Standard 10 ft (3.05 m); Body mass: 80 kg; Standing reach: 8 ft; Ball clearance above the rim: 6 in.
Results — Minimum vertical leap = 30 in; Jumping energy = 597.8134 J; Take-off speed = 13.92 km/h; Hang time = 0.7884 s.
Key terms
- Vertical leap
- Height gained from a standing or running jump.
Frequently asked questions
How high must I jump to dunk?
Typically 50–75 cm (20–30 in) for average-height adults.
What is standing reach?
The highest point you can touch with one arm, feet flat.
Does a bigger hand help?
Yes – palming the ball needs less clearance.
What is a typical vertical jump?
About 40–60 cm for active adults; elite athletes exceed 90 cm.