Average Reaction Time: What's Normal?

For a simple visual test, where you press a button the moment a light or shape appears, careful studies put average adult reaction time at roughly 210 to 250 milliseconds. There’s no single “normal” number, and results differ between labs partly because the testing hardware and software add their own delays (Woods et al., 2015). In one large calibrated study, adults averaged 231 ms, or 213 ms once the computer’s own delays were subtracted (Woods et al., 2015). Other recent computer-based studies report averages from 233 ms to nearly 400 ms (same source). Reacting to a beep is usually a little faster than reacting to something you see (Jain et al., 2015), and having to choose between several responses adds time (Wright et al., 2011). For a driver who has to brake for a hazard, road designers assume 2.5 seconds of perception-reaction time (Federal Highway Administration).

Typical simple reaction times

The methods in these studies differ, and that explains part of the spread.

Study	Who was tested	How	Average
Woods et al., 2015, experiment 1	1,469 adults aged 18 to 65 in New Zealand	Visual target, gaming mouse	231 ms (213 ms corrected for hardware delay)
Woods et al., 2015, experiment 2	189 adults aged 18 to 82 in California	Same task	237.8 ms (220 ms corrected)
Jain et al., 2015	120 medical students aged 18 to 20	Red circle on a laptop; fastest of five tries	247.6 ms
Kasozi et al., 2018	57 medical students in Uganda	Catching a dropped ruler	148 ms

Woods and colleagues note that delays in computer hardware and software can add up to 100 ms to measured reaction times (Woods et al., 2015). Their own mouse and display added about 18 ms (same source). Between 1884 and 1893, Francis Galton recorded visual reaction times of 181 to 189 ms in people aged 18 to 60. The Woods team says its delay-corrected figures are similar to his (same source).

Sound, sight and touch

In the Jain study, students reacted faster to a beep than to a red circle: 228.0 ms versus 247.6 ms (Jain et al., 2015). The authors cite long-standing textbook figures of about 190 ms for light and 160 ms for sound in college-age people, and another estimate of 180 to 200 ms for sight versus 140 to 160 ms for sound (same source). They also cite research that an auditory signal reaches the brain in 8 to 10 ms, compared with 20 to 40 ms for a visual one (same source).

Touch can be quickest of all, though not by much. With the ruler-drop method, the Uganda study measured 139 ms for touch, 141 ms for sound and 148 ms for sight (Kasozi et al., 2018). A 2024 online study found the same order on a learning task: touch cues were fastest, sound was in the middle and visual cues were slowest. People also responded faster on touchscreen mobile devices than on computers (Sun et al., 2024).

Simple vs. choice reaction time

The researchers Luce and Welford described three kinds of reaction time, as summarized by Jain et al., 2015:

• Simple reaction time has one stimulus and one response.
• Recognition reaction time means responding to some stimuli and ignoring others.
• Choice reaction time has several stimuli, each with its own response.

Choice reaction time follows Hick’s law, published by W. E. Hick in 1952 (Proctor & Schneider, 2018). It says reaction time grows in a straight line with the logarithm of the number of possible choices (Wright et al., 2011). In practice, each doubling of the choices can add as much as 100 to 150 ms, depending on the stimuli, the responses and how practiced you are (same source). Going from 2 options to 4 to 8 costs roughly the same amount each time. Hick’s law is still treated as a basic rule of interface design (Proctor & Schneider, 2018).

What changes your reaction time

Age

Studies agree that reaction time slows with age, but they describe the pattern differently. Woods and colleagues found simple reaction time rising steadily by about 0.55 ms per year, from about 218 ms in 18- to 24-year-olds to 239.1 ms in 59- to 65-year-olds (Woods et al., 2015). A reanalysis of 7,130 UK adults found little slowing of simple reaction time until around age 50, while choice reaction time slowed throughout adulthood (Der & Deary, 2006).

Fatigue and sleep loss

In a study of 39 transport workers and soldiers, after 17 to 19 hours without sleep, performance on some tests matched or was worse than performance at a 0.05% blood alcohol level. Response speeds were up to 50% slower on some tests (Williamson & Feyer, 2000). Sleep loss slows responses overall, adds more lapses (very slow responses) and brings a more modest rise in false starts (Basner & Dinges, 2011). Even a single session can wear you down: in the Woods study, average times rose from 228.1 ms in the first block of 20 trials to 237.2 ms in the last (Woods et al., 2015).

Practice

Practice is one of the factors that can affect reaction time (Jain et al., 2015). For choice tasks, some researchers found that training shortens reaction time, and that in well-trained people the number of choices stops making a difference (Keramati et al., 2011). Proctor and Schneider list practice among the known challenges to Hick’s law (Proctor & Schneider, 2018).

Distraction

A meta-analysis of 33 studies found that phone tasks raised drivers’ reaction times by an average of 0.25 seconds. Of the driving measures studied, reaction time took the biggest hit, and handheld and hands-free phones slowed drivers by similar amounts (Caird et al., 2008).

Reaction time behind the wheel

Road design uses much longer times than a lab button press, because a driver has to notice a hazard, recognize it, decide what to do and start braking. Those are the four elements of perception-reaction time listed in Federal Highway Administration (FHWA) guidance (FHWA aging-driver handbook).

The AASHTO Green Book’s stopping sight distance criteria assume a 2.5-second perception-reaction time. That value exceeds the reaction time of the 90th-percentile driver (FHWA). FHWA’s handbook on older road users says the value was chosen because it was adequate for about 90% of drivers (FHWA aging-driver handbook).

Typical drivers are faster. FHWA says normal perception-reaction times run from about 0.75 to 1.5 seconds, depending on alertness, fatigue, alcohol and age. For comparison, it uses 1.1 seconds for the mean driver (FHWA). On the road, age made less difference in the studies FHWA cites: field and simulator studies of aging drivers found that brake reaction times to unexpected hazards didn’t differ significantly by age, and that virtually all responses fit within 2.5 seconds (FHWA aging-driver handbook).

A car going 60 mph covers 88 feet each second, so in 2.5 seconds it travels 220 feet before the driver starts braking. That distance is plain arithmetic from the speed.

How to measure your own reaction time fairly

1. Take many trials and use the median. Reaction times have a right-skewed distribution, and the data often contain outliers (Morís Fernández & Vadillo, 2020). Robust measures such as the median are much less affected by outliers than the mean (Ratcliff, 1993).
2. Use the same number of trials every time. Medians from small samples tend to overestimate, by as much as 50 ms with small, highly skewed samples. So don’t compare medians from sessions with different trial counts (Miller, 1988).
3. Randomize the wait. The standard psychomotor vigilance test shows each stimulus after a random wait of 2 to 10 seconds (Basner & Dinges, 2011). Woods and colleagues found that reaction times were slower when the gap between stimuli was shorter (Woods et al., 2015).
4. Throw out false starts. The vigilance test counts any response without a stimulus, or faster than 100 ms, as a false start (Basner & Dinges, 2011). The Woods study only accepted responses between 110 and 1,000 ms (Woods et al., 2015).
5. Warm up first. Each person in the Woods study got 20 practice trials before the 120 that counted (Woods et al., 2015).
6. Keep your setup the same. Use the same device, hand and kind of signal each time, since hardware delays and the type of stimulus both change the number. Test when you’re rested and nothing is distracting you.

To test how many items you can hold in mind at once, see our guide to the digit span test.