A typical simple reaction time for an adult, pressing a button when a light appears, is a little over 200 milliseconds: 230.8 ms on average across 1,469 adults in one large study. Reaction time slows only slightly with age, about half a millisecond a year, and moves more with lost sleep, time of day and the device doing the measuring.
Listen to this article, about 14 minutes. A synthetic voice reads the article and announces each section title as it begins; tables are read row by row and the questions at the end are left out.
Recorded 9 November 2026 from the article as published that day. Press a chapter to jump there; the highlighted line is what is playing. A play button sits beside every section heading, and once you scroll past this player a bar at the bottom of the screen keeps the controls in reach. Tap or click any sentence to hear the reading start from there.
On this page: mean simple reaction time by age band from a 1,469 person study, a cited table of what sleep loss, caffeine, alcohol, exercise and time of day do with the effect sizes, what about 40 self testers report about their own scores, and a checklist of the conditions the studies held steady.
Think you already know this? Five questions, one minute.
Every answer is on this page. Answer from what you know now; the page fills in the rest.
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1. In the 2015 study of 1,469 adults, how much of the measured reaction time belonged to the equipment rather than the person?
The researchers measured the delay of their own computer, screen and button and subtracted it, taking the mean from 230.8 ms to 213 ms. Woods et al. 2015 Read the section
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2. What did Der and Deary find for simple reaction time in 7,130 adults from the UK Health and Lifestyle Survey?
Simple reaction time showed little slowing until around 50, while choice reaction time slowed across the whole adult age range. Der and Deary 2006 Read the section
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3. In the 2010 meta-analysis of 24 to 48 hours without sleep, which kind of task showed the largest effects?
Simple attention took the biggest hit, g of minus 0.732 for reaction time and minus 0.762 for lapses in the paper’s table, while reasoning barely moved. Lim and Dinges 2010 Read the section
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4. What overall effect of a single bout of exercise on cognitive performance did the 2012 meta-analysis of 79 studies find?
The pooled effect was small and positive, and depended on duration, intensity, the task and fitness. Chang et al. 2012 Read the section
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5. What range of time of day differences in reaction time did the 2023 systematic review report?
The review of 11 studies in healthy adult men reported reaction time differences of 9.0 to 34.2 per cent, and said no study met every chronobiology standard. Munnilari et al. 2023 Read the section
What is a typical reaction time for an adult?
Reaction time is the gap between something appearing and you responding to it. Simple reaction time has one signal and one response: a light comes on, you press. It is the oldest measure in experimental psychology.
The cleanest modern figure comes from Woods and colleagues, writing in Frontiers in Human Neuroscience in 2015. They tested 1,469 adults aged 18 to 65 in Rotorua, New Zealand, each doing 20 practice trials and then 120 real ones. The mean simple reaction time was 230.8 ms. Then they did something most online tests never mention: they measured the delay added by their own computer, screen and button, and subtracted it. The corrected figure was 213 ms. About 18 ms of every result, in other words, belonged to the equipment, not the person.
Men and women did not differ significantly. People slowed as the session wore on, from 228.1 ms in the first block of 20 trials to 237.2 ms in the last, which is what boredom looks like in milliseconds. And a reminder for every number on this page: these are averages across a sample of strangers. They describe a population, not any one reader.
The headlines claiming the Victorians reacted faster come from Francis Galton’s tests of the 1880s, where visual reaction times ran 181 to 189 ms. Woods and colleagues argue the gap is mostly method and found no evidence of slower processing today. Others disagree, in a commentary titled, with some confidence, The Victorians were still faster than us. The argument is about equipment and arithmetic.
How much does reaction time change with age?
Less than the anxiety around it suggests. In the Woods sample, reaction time rose by about 0.55 ms for every year of age. The youngest band averaged 217.9 ms and the oldest 239.1 ms: a difference of about 21 ms across four decades. Reaction time is not the only body skill that shifts with age: our page on how kinesthetic awareness is tested and how it changes with age covers the sense of where your limbs are, and the falls figures that make it matter.
| Age band | People tested | Mean simple reaction time (ms) |
|---|---|---|
| 18 to 24 | 86 | 217.9 |
| 25 to 31 | 115 | 221.0 |
| 32 to 38 | 201 | 224.8 |
| 39 to 45 | 273 | 227.7 |
| 46 to 51 | 276 | 233.6 |
| 51 to 58 (as printed) | 272 | 236.4 |
| 59 to 65 | 246 | 239.1 |
The band labels are copied as the paper prints them, overlap included. A second large dataset tells a slightly different story. Der and Deary, in Psychology and Aging in 2006, reanalysed 7,130 adults from the UK Health and Lifestyle Survey and found that simple reaction time showed little slowing until around 50, while choice reaction time, where you pick between responses, slowed right across adulthood. One study shows a gentle slope from the start, the other a flat line that bends later. Both agree the slowing is small.
A 45 year old faster than the 25 to 31 band has not cheated time, and a 35 year old slower than the 59 to 65 band has not been diagnosed with anything. A change in memory or thinking that you or the people close to you have noticed is a reason to talk to a doctor, whatever any reaction test says.
What does losing a night of sleep do to reaction time?
This is where reaction time really moves. In 2010 Julian Lim and David Dinges pooled 70 articles covering 147 cognitive tests in a meta-analysis in Psychological Bulletin on what 24 to 48 hours without sleep does to thinking. Simple attention took the biggest hit of any domain. For reaction time on those tasks the pooled effect size was minus 0.732 (Hedges’ g, across 26 analyses), and for lapses, the moments someone fails to respond at all, minus 0.762 in the paper’s table and minus 0.776 in its abstract. Both count as large. Reasoning, by contrast, barely moved.
Two cautions. These studies kept people awake for a whole night or more in a laboratory, which is not the same as sleeping five hours instead of seven. What a week of shorter nights did in the 2003 sleep restriction studies is set out in our page on what one short night does to sleep and memory. And an effect size is an average shift across groups, not a forecast for one person. What the paper does show is that a simple reaction task is one of the more sensitive places sleep loss shows up.
Do caffeine, alcohol and exercise change reaction time?
Each does something, and none of it is what the adverts claim. On caffeine, the European Food Safety Authority looked at the evidence when judging a label claim about alertness. In its 2014 opinion it noted that most studies found no effect on reaction time below 75 mg per serving, and most studies at 75 mg or more found reaction time fell. That threshold is the condition for a food label claim in the EU. It is not a dose suggestion, and this page makes none.
On alcohol, a review of 112 articles by Herbert Moskowitz and Dary Fiorentino for the US National Highway Traffic Safety Administration found that some driving related skills are impaired from any significant departure from zero blood alcohol, and that by 0.05 grams per decilitre the majority of studies reported significant impairment. The thresholds vary, the authors note, because the tests are not standardised.
On exercise, Chang and colleagues in Brain Research in 2012 pooled 79 studies and found a small positive effect of a single bout on cognitive performance, g = 0.097, depending on duration, intensity, task and fitness. A 2024 Bayesian meta-analysis of 113 studies and 651 effect sizes in young adults found a similar small benefit, g = 0.13, including faster reaction times. Small is the honest word. Nobody has found the ten point jump the brain training advert keeps promising. The long trials behind those adverts, and what brain training apps improved and what they did not, are set out in a separate cited table.
| Factor | Source | What was found | The caveat |
|---|---|---|---|
| Age | Woods et al. 2015, 1,469 adults | About 0.55 ms slower per year | Population average |
| 24 to 48 hours awake | Lim and Dinges 2010, 70 articles | g = minus 0.732 for simple reaction time | Whole nights in a laboratory |
| Caffeine | EFSA opinion, 2014 | Mostly no effect below 75 mg, mostly faster at 75 mg or more | A label claim ruling, not advice |
| Alcohol | NHTSA review, 112 articles | Most studies show impairment by 0.05 grams per decilitre | Tests not standardised |
| One bout of exercise | Chang et al. 2012, 79 studies | g = 0.097, small | Depends on duration and intensity |
| Time of day | Munnilari et al. 2023, 11 studies | 9.0 to 34.2 per cent apart, often best in early evening | Healthy young men only |
Is reaction time faster at a particular time of day?
Usually later rather than earlier, though the evidence is messier than any listicle admits. A 2023 systematic review in Sleep and Breathing by Madhavi Munnilari and colleagues found 11 studies that met its rules, all in healthy adult men, and reported reaction time differences between times of day ranging from 9.0 to 34.2 per cent. Most studies it discusses found simple reaction time best in the early evening, around 16:00 to 17:00.
One study inside the review, of 20 men, found an average of 237.08 ms at 18:00 and 258.53 ms at 14:00, the post lunch dip doing what post lunch dips do. Another, of 20 medical students in 2021, found no time of day effect at all. The reviewers said no study met every requirement for chronobiology research. The practical point is modest: a check at 8 in the morning and one at 6 in the evening are not measuring the same conditions.
What do people who test their own reaction time report?
The best public record we found is an August 2026 thread on r/aimlab, a community for an aim training game, where someone asked people to post their age and average reaction time. The scraped page held 130 comments, and about 40 people gave a number, aged from 19 to 56. What follows is paraphrased testimony, not a finding.
The numbers are startlingly fast next to the studies: most posted between about 120 and 200 ms, far below the 230.8 ms laboratory mean. The thread itself explains why. One commenter warned of a large hardware bias and said scores from different tests cannot be compared. Another said switching their monitor to a slower refresh rate added about 15 ms, and pressing a key instead of a mouse button another 15. One reported about 350 ms on a phone against 150 with a mouse. These are gamers who practise, the opposite of a random sample.
The more useful pattern is within each person. One commenter scored 172 after a poor night against a usual 150. Another said 135 on their best days and 150 on worse ones, unchanged since 20. One person in their twenties said their reaction time stayed the same when drunk and only their focus went, one person’s impression set against a review that found some skills impaired from any significant departure from zero. And a 43 year old on 174 ms prompted the original poster to wonder whether people exaggerate the decline with age, which the Woods figures suggest is a fair question.
Where the accounts agree with the studies: the same person’s number moves with sleep, focus and time of day, and the equipment matters as much as age. Where they go beyond them: self reported best scores on home hardware cannot be set beside a laboratory average, and nobody in the thread can tell you whether their slower days meant anything.
How can one person’s reaction time checks be made comparable?
By copying what the researchers held steady. The checklist on this page lists the conditions the studies above controlled. The short version: same device, same input, same time of day, a few practice trials first, and many trials rather than five, judged by the middle of the results rather than the best one. Woods and colleagues showed what that care buys. In a second 2015 study, 48 people repeated the test in three weekly sessions; the test retest reliability was 0.83 and there were no significant learning effects across sessions.
If you want to see how your own reaction time moves across a week of good and bad nights, the free Awareness Score check-in includes it. It is four short games, Star Trails, Picture Memory, Grid Span and Reaction, about five minutes, with a score from 0 to 100 compared only with your own earlier check-ins. Scores rise a little with practice and move with sleep, stress and the time of day, which is why the guide to comparing one daily check-in with another insists on the same time and the same way. How stress moves memory, and how much of it recovers, is covered in the evidence on stress and memory loss, study by study. Reaction time is only one slice of attention; the article on what awareness means covers the part where people miss a gorilla.
The app is not a diagnosis, a medical test or a medical device. It does not detect, screen for or measure any condition, and it does not compare you with anyone else. Mufy Pachorawala, who writes these pages, runs it, and he is not a doctor or a psychologist, which is why every figure above is linked to the people who did the measuring.
The conditions the cited studies held steady before measuring reaction time
Each item restates what one of the studies linked on this page controlled or found. Ticking them makes one person’s checks more comparable with each other; it scores, screens and diagnoses nothing.
These are research conditions, not a test. A noticeable change in memory or thinking, or one that worries you or the people close to you, is a reason to talk to a doctor, whatever any reaction test shows.
Frequently asked questions
What is the difference between simple and choice reaction time?
Simple reaction time has one signal and one response, such as pressing a key when a light comes on. Choice reaction time has several signals, each with its own response, so the brain has to pick. Choice reaction time is slower, and Der and Deary found it slowed across the whole adult age range while simple reaction time changed little until about 50.
Why is my online reaction test result different from the studies?
Online tests run on different screens, mice, keyboards and phones, each adding its own delay, and many use only five trials. Woods and colleagues measured about 18 ms of delay in their own laboratory equipment. A result from one setup cannot be compared fairly with a laboratory average or with someone else’s setup.
Is 300 milliseconds a slow reaction time?
A single number from an unknown device says very little. The laboratory averages on this page are for one kind of task and one set of equipment, and they describe populations rather than individuals. If you are worried about a change in how quickly you think or respond, that is a conversation for a doctor, not a reaction test.
Do men and women have different reaction times?
In the 1,469 person Woods study, simple reaction times did not differ significantly between men and women. Der and Deary reported some sex differences in the UK survey, most notably in the variability of choice reaction time rather than in simple reaction time.
Can video games improve reaction time?
Gamers in public forums report fast scores, but they also tend to use faster monitors and practise the test, so their numbers cannot show that games caused the speed. This page found no study it could verify on the day that answers the question, so it makes no claim either way.
Does a slow day on a reaction test mean something is wrong?
Not on its own. Reaction time moves with sleep, time of day, focus and the device, and the studies above show swings within the same people. A noticeable change in memory or thinking, or one that worries you or the people close to you, is a reason to talk to a doctor.
Finished the page? The same five questions from the top, to see what stuck.
General information from published research and public health bodies, checked on the date shown. It is not medical advice, and the Awareness Score app is not a medical test. If your memory or thinking has changed noticeably, or worries you or the people close to you, talk to your doctor.
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