About Ruler Drop Test
The ruler drop test measures reaction time without a stopwatch. A partner holds a ruler vertically with the zero mark between your open fingers and lets go without warning, and you catch it. The distance it fell gives the time from the free fall equation d = ½gt², rearranged to t = √(2d ÷ g). A catch at 17 cm corresponds to about 186 milliseconds. Averaging at least five attempts reduces the effect of anticipation.
How to use Ruler Drop Test
- Fill in "Catch distances (cm), separated by commas" and "Gravity".
- The result appears below and updates as you type.
- Copy the result with the copy button, or download it as a file where that is offered.
Questions about Ruler Drop Test
What is a typical ruler drop result?
Most adults catch the ruler between about 15 and 25 cm, which is roughly 175 to 225 milliseconds. Results depend on attention, practice, and whether you anticipated the release, so compare your own averages over time.
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