Calculator
Convert the time your ball takes down the lane into mph, or work backwards from a speed you already know.
Ball speed
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Enter a time to convert.
This is the single most confusing thing about bowling ball speed, and it explains most of the arguments about it: a ball is measured at two different points, and the numbers do not match.
Release speed is measured just after the ball leaves your hand. Pin speed is measured as it arrives. Friction and the hook phase bleed energy the whole way down, so pin speed is typically around 2 to 3 mph lower. When a broadcast quotes a professional at 21 mph and your house monitor says 16, you may not be as far apart as it sounds — you might be comparing two different measurements.
Film from the side at 60 frames per second if your phone allows it, then count frames from the moment the ball crosses the foul line to the moment it strikes the headpin. Divide the frame count by 60 for your time in seconds. Stopwatch timing works but human reaction adds roughly a fifth of a second, which at these distances is a full mph or more of error.
| Speed at the pins | Who |
|---|---|
| Under 13 mph | Slow. The ball may burn up its energy before the pocket. |
| 15–18 mph | The bulk of league bowlers. |
| 19–21 mph | Strong amateur and professional range. |
Speed only matters relative to your rev rate. Throw hard with few revs and the ball never finishes into the pocket; throw slowly with heavy revs and it hooks out early. The ratio between the two is what produces a repeatable shot, which is why coaches talk about matching speed to revs rather than maximising either. If you have not measured your revs, the rev rate calculator is the other half of this picture.