How to use
This calculator compares the height your fingertips reach with a rim and an extra height you choose. It is for players who want a measurable jump target, or who want to compare a recorded vertical jump with that target. It does not infer arm length from your height. Two people of the same height can have different standing reach.
- Choose inches or centimeters. Changing the unit converts the existing measurements.
- Enter standing reach measured from the floor to your highest fingertip with your feet flat. Keep footwear and the reaching arm consistent with the jumping measurement.
- Enter your recorded vertical jump, rim height and extra height above the rim. Press Calculate, then read the required jump and signed margin.
- Use Copy result to keep the calculated values. Editing a field clears the confirmed result; Calculate again after finishing your changes.
Measure reach, then choose a target
Standing reach is a height above the floor. Vertical jump is a difference between two heights. If your hand reaches 124 inches in a jump and your standing reach is 96 inches, enter a vertical jump of 28 inches, not 124. Do not compare a standing jump measurement with an approach jump and treat the difference as a change in ability.
The NBA rim reference is 120 inches, or 304.8 centimeters. Measure an adjustable or nonstandard hoop instead of assuming it has this height. Extra height is a personal clearance target: 6 inches is the editable example used here, not an official dunk requirement or a universal minimum. Ball size, grip, takeoff and control can change how much clearance you need.
Read the calculation
Target height = rim height + extra height. Required vertical jump = maximum of zero and target height − standing reach. Jump reach = standing reach + vertical jump. Margin = jump reach − target height. A negative margin means you are below your chosen target; a positive margin means you are above it.
The solid height lines share a floor and height scale. A marks standing reach, B marks jump reach, C marks the rim, and the dashed line marks your target. The small person only illustrates reaching; its body proportions are not inferred from your input. The diagram responds before Calculate, while Copy uses only a confirmed result.
Worked examples
96 in reach + 28 in jump, with a 120 in rim and 6 in extra: required jump 30 in; jump reach 124 in; target margin −2 in. Touching the rim requires 24 in.
240 cm reach + 90 cm jump, with a 305 cm rim and 15 cm extra: required jump 80 cm; jump reach 330 cm; target margin +10 cm. The changed rim is a custom measurement.
Limits and common questions
All heights use the selected unit. Decimal points and decimal commas are accepted; thousands separators, feet-and-inches text and negative heights are not. The input ranges are interface limits, not recommended athlete measurements. Values keep calculation precision internally and display up to two decimal places. No training plan or success probability is generated.
Why not enter my body height?
Your actual standing reach is the quantity needed by the height calculation. Measuring it avoids an assumed body proportion.
Does a positive margin mean I can dunk?
It means your fingertips reach the selected geometric target. It does not establish that you can control and finish with a ball.
Can I use a shorter hoop?
Yes. Enter its measured rim height and retain your own reach and jump measurements in the same unit.
What does Clear do?
Clear removes measurements and the confirmed result while preserving the unit. Empty fields can show muted examples again after blur; this does not restore an old result.