Vertical Jump: Hang Time

▶ Measure your real vertical jump with just your phone. Record a slow-motion clip, mark the takeoff and landing frames, and the flight time turns into your jump height in inches or centimeters. ▶ Prefer speed? Use the quick test: hold your phone and jump, and the motion sensor finds the falling window to estimate hang time and height on the spot. Run three attempts and take the best. ▶ The dunk calculator does the math you actually care about. Enter your height, standing reach and rim height, and see exactly how many inches of vertical you still need to throw one down. ▶ Track every session. Save dates, watch your best jump climb, and read the trend on a simple graph so you know your training is working. ▶ Share a clean result card, switch units freely, and use it in any language. Works without an account. Results are estimates from your video frames or sensor motion; accuracy depends on your camera frame rate and how you mark takeoff and landing. This is a fitness tool, not a medical or performance guarantee.