How fast are your reactions?
A reaction time under 100 ms is not a reaction — it is a guess. That is exactly why sprint starts are disqualified below it.
Almost exactly an average adult, visual
0.25 s is slower than 4 of the 8 references on this page.
Reference figures are measurements and are rounded; the unit conversion behind them is exact.
| Reference | Size | Yours ÷ theirs | Note |
|---|---|---|---|
| nerve signal to the hand | 0.02 s | 12.5× | |
| sprint false-start threshold | 0.1 s | 2.5× | Below this is ruled a guess |
| elite sprinter off the blocks | 0.13 s | 1.92× | |
| visual reaction, trained | 0.18 s | 1.39× | |
| average adult, visual | 0.25 s | 1× | |
| average adult, tired | 0.35 s | 0.714× | |
| driver braking reaction | 0.7 s | 0.357× | Used in stopping-distance tables |
| legally impaired driver | 1.2 s | 0.208× |
Worth knowing
- Athletics rules disqualify any start reacted to in under 0.100 s, on the grounds that no human can process the gun that fast.
- Auditory reactions are about 40 ms faster than visual ones, which is why races start with a gun rather than a light.
Frequently asked
What is a good reaction time?
Around 250 ms for a visual cue is average for an adult. Under 200 ms is fast, and trained athletes and gamers cluster in the 150–200 ms band.
Why is driver reaction time given as 0.7 seconds?
Because it includes perceiving the hazard, deciding, and moving the foot — not just reacting to an expected signal. Real emergency responses run 1.5 s and longer.