I got within an inch of rim so I just extrapolated based on that. I know for a fact that I jumped 35" in the gym, but at my house it might've been as low as 34". I'm in medical school and we have a basketball court, so I sneak in some jumps there from time to time. My ceiling is exactly 9' and I can palm it with both hands. My vertical jump device said 37-38", so I think the higher the vertical, the less accurate it is.