Average Reaction Time

The average simple reaction time of a young adult is about 190 milliseconds (ms) to a light and about 160 ms to a sound. Those are laboratory figures, measured with a lamp or a buzzer and a dedicated button. In a browser test on an ordinary computer or phone, the same person usually scores around 250 ms, because the screen and the mouse add their own delay. Below you will find where these numbers come from, what counts as a good reaction time, how it changes with age and what sprinters manage. To get your own number, take the reaction time test.

The laboratory averages

Reaction time research goes back to the 19th century, and some numbers have proved remarkably stable. Robert Kosinski's literature review on reaction time (Clemson University) puts it this way: for about 100 years, the accepted mean simple reaction times for college-age people have been about 190 ms for light and about 160 ms for sound. The review cites A. T. Welford's book Reaction Times (1980) and older studies going back to Francis Galton.

Sound wins because the signal gets to the brain faster. According to the same review, an auditory signal takes about 8–10 ms to reach the brain and a visual one about 20–40 ms. "Simple" means there is one signal and one response. As soon as you have to choose between responses, reaction time grows, which you can try in the choice reaction time test.

Why online tests show about 250 ms

A browser cannot measure your nerves directly. Between the moment the code changes the colour and the moment it sees your click, several devices are involved: the screen has to draw the new frame, and the mouse, keyboard or touchscreen has to report the press. Together this usually adds 20 to 60 ms on an ordinary setup. Add that to the laboratory figure and you land close to 250 ms, which is why our test compares you with an estimated online average of about 250 ms.

That makes "good" a relative idea online. On our result card the steps are:

• under 180 ms: Excellent
• 180 to 249 ms: Faster than average
• 250 to 319 ms: About average
• 320 ms or more: Slower than average

A single very fast press can be partly a lucky guess, so look at your average of five attempts rather than your fastest one. Compare results on the same device: a high refresh rate screen and a wired mouse report your press sooner than an old laptop's touchpad or a Bluetooth mouse, so two devices can give the same person different scores.

Reaction time by age

Reaction time is not fixed for life. Kosinski's review, citing Welford (1977), describes the general pattern: reaction time gets shorter from childhood into the late 20s, then lengthens slowly until the 50s and 60s, and lengthens faster from the 70s onwards.

A large British survey gives a clearer picture of adulthood. Geoff Der and Ian Deary analysed data from 7,130 adults in the UK Health and Lifestyle Survey (published 2006). They found that simple reaction time changed little until about age 50, while choice reaction time, where you must pick the right response, slowed across the whole adult age range.

The studies do not give a reliable "normal" millisecond value for each birthday, so we do not publish an age table. If you compare yourself with family members, do it on the same device and look at the trend over several rounds.

How fast are athletes?

Sprinters' reaction times are among the best measured in sport, because their starting blocks detect the moment they push. Espen Tønnessen and colleagues studied 1,319 sprinters at the athletics World Championships from 2003 to 2009 (published 2013). The average reaction time was 0.166 seconds (166 ms) for men and 0.176 seconds (176 ms) for women. Male finalists were fastest in the final itself, at 0.142 seconds on average.

These are reactions to the sound of the starting gun, so they should be compared with the laboratory sound figure of about 160 ms, not with a browser test. World Athletics rules treat a reaction faster than 0.1 seconds as a false start, on the basis that a genuine reaction to the gun cannot be that fast.

If you want to compare your own eyes and ears, take the audio reaction time test on the same device: most people react faster to a beep than to a colour change, as the laboratory figures suggest.

What slows you down and what helps

Kosinski's review lists many factors that shift reaction time. The ones you can do something about:

• Tiredness and sleepiness. Mental fatigue, especially sleepiness, has the largest effect. A short night is the most common reason for a sudden slow score.
• Distraction. Anything that splits your attention adds milliseconds. Look at the box, not at your phone.
• Arousal. Reaction time is fastest at a moderate level of alertness and worse when you are either too relaxed or too tense.
• Fitness. Welford (1980) reported that physically fit people had faster reaction times.
• Warning. People react faster when they know a signal is coming soon, which is why a focused start helps.
• Alcohol and some medicines slow reactions. Never use an online score to decide whether you are fit to drive.

Practice mostly helps you keep your finger ready and your attention steady; short daily rounds work better than one long session. For a game-like mix of speed and accuracy, the aim test adds moving targets.

When to talk to a doctor

A single slow round means little. If you notice that your reactions have become clearly slower in everyday life, for example while driving, or the change comes with other symptoms such as numbness, dizziness or confusion, talk to a doctor. An online reaction test is a self-check for curiosity and practice, not a medical test.

Sources

• Kosinski RJ, Cummings J. The scientific method: an introduction using reaction time. In: Karcher SJ, ed. Tested Studies for Laboratory Teaching, Vol. 20. Association for Biology Laboratory Education (ABLE), 1999: 63–84. Appendix C: A literature review on reaction time.
• Welford AT, ed. Reaction Times. Academic Press, 1980.
• Der G, Deary IJ. Age and sex differences in reaction time in adulthood: results from the United Kingdom Health and Lifestyle Survey. Psychology and Aging. 2006;21(1):62–73.
• Tønnessen E, Haugen T, Shalfawi SAI. Reaction time aspects of elite sprinters in athletic world championships. Journal of Strength and Conditioning Research. 2013;27(4):885–892.
• World Athletics. 100 metres: how it works (false starts).

Frequently asked questions