🏀 Dunk Calculator
Estimate the vertical jump required to dunk and see how close you are to clearing the rim.
Standard basketball rim is 10 feet.
Measure from the floor to fingertips with both arms extended.
Allow extra inches to clear the rim with the ball (5–8 inches typical).
How to Use This Calculator
Measure Standing Reach
Stand flat-footed, reach up with both hands, and record the highest fingertip mark.
Test Your Vertical
Use a Vertec or chalk test to capture your max jump height in inches.
Set Rim and Clearance
Adjust rim height and add a clearance buffer so the ball clears the rim.
Review Output
Compare required and current vertical jump numbers to plan training.
Formula
Required Vertical = Rim Height + Clearance − Standing Reach
The formula compares how high your hands can reach (standing reach) against the rim height plus the extra space needed to clear the ball through the hoop. The difference gives the minimum vertical jump to dunk.
Variables
- Rim Height: Total inches from floor to rim.
- Clearance: Extra inches to fit the ball through (typically 6").
- Standing Reach: Height you can touch without jumping.
Example
Standing reach 92", rim 120", clearance 6" → Required vertical = 120 + 6 − 92 = 34". A 30" vertical is 4" short, so you need another 4" to dunk comfortably.
Understanding Dunk Requirements
Dunking depends on a combination of approach speed, vertical jump, standing reach, ball control, and timing. Taller players with long wingspans need less vertical, while shorter athletes can compensate with stronger leaping ability.
Benchmarks
- 30"+ Vertical: Many players can dunk with the right reach.
- 35"+ Vertical: Provides comfortable clearance and allows for variations.
- 40"+ Vertical: Elite leaping, suitable for advanced dunk contests.
Improvement Tips
- Strengthen lower body through squats, deadlifts, and calf raises.
- Incorporate plyometric drills like box jumps and depth jumps.
- Improve approach mechanics—efficient steps can add several inches to jump height.
- Practice palming or controlling the ball to convert the vertical into an actual dunk.
Frequently Asked Questions
How accurate is the calculator?
It provides a physics-based estimate. Real-world results depend on timing, ball control, and approach speed, so treat it as a guideline rather than an absolute guarantee.
What if I can touch the rim but not dunk?
You likely need more clearance to control the ball. Increase vertical jump, improve grip strength, or use a lighter ball during practice to build confidence.
Does jumping off one foot vs. two feet matter?
Yes. One-foot jumpers often rely on speed and have different technique requirements than two-foot jumpers. Use the calculator with the vertical style that matches your approach.
What if I play on a lower rim?
Adjust the rim height inputs to match your hoop. The calculator instantly recomputes the required vertical for 9', 9'6", or any custom rim height.
Can I improve my standing reach?
A small boost is possible through shoulder mobility, stretching, and posture training. However, most of the improvement must come from increasing vertical jump or technique.