Ruler Drop

About Ruler Drop

Ruler Drop is a free reaction-time test based on the classic ruler-catch experiment. Click to start a round, wait for the ruler to fall, and click as soon as it starts to drop. The game measures your reaction time in milliseconds and averages five rounds into a single result and grade.

It takes less than a minute and needs no equipment other than your mouse or touch screen, so it is easy to repeat and compare with friends.

How scoring works

• A round measures the time between the ruler starting to fall and your click. A lower number is better.
• After five rounds you see your average in milliseconds and a grade: Lightning (under 180 ms), Excellent (under 220 ms), Good (under 260 ms), Average (under 320 ms) or Keep practicing.
• Clicking before the ruler falls shows 'Too soon!'. Your best average is saved in your browser.

Tips to improve

• Keep a relaxed gaze on the middle of the ruler area and avoid staring at the edge.
• Do not guess the timing. Waiting for the drop gives a better average than clicking early.
• Keep your finger on the button so that you only have to press, not move.
• Your first rounds are usually the slowest. Play a few runs before judging your reflexes.

Frequently asked questions

What is a good reaction time?

In this game, an average under 260 ms is graded as Good, and under 220 ms as Excellent. Human Benchmark reports a median of 273 ms from the data it has collected (humanbenchmark.com/tests/reactiontime), and it notes that your screen and computer add their own delay. Results depend on your screen, mouse and device.

Why is my result different on a phone?

Touch screens and displays add their own delay, so a phone usually gives a slower number than a mouse on a fast monitor.

Is my result saved?

Your best average is stored in your browser and can be sent to the ranking if you choose a name.