What Is a Good Reaction Time? Why 250ms Is Normal and How to Measure It Properly

Most people land somewhere between 200 and 300ms on an online reaction test. You feel like you clicked the instant the screen changed, so seeing 0.25 seconds feels unfair. But that number is close to a physical floor, not a personal failing.

1. Why sub-200ms is so hard

Before your finger moves, a signal has to travel a full circuit:

1. Light hits the retina and becomes an electrical signal
2. The signal travels the optic nerve to the brain
3. The brain decides "now"
4. A motor command runs down to the finger muscles
5. The muscle actually contracts and presses

Each step costs tens of milliseconds. So even for the simplest "press when it lights up" task, 200–250ms is the normal range. If you see something in the 100s, it usually means you anticipated the signal and pressed early rather than reacted to it.

One quirk worth knowing: you react to sound faster than to light. The auditory path to the brain is shorter — which is exactly why sprint races start with a gunshot rather than a light.

2. Why the number on screen is inflated

This is the part most tests skip. What you see is not purely your reaction time.

Refresh rate. A 60Hz monitor redraws 60 times per second, so one frame is 16.7ms. Even after the signal changes, you wait about 8ms on average for it to actually appear. At 144Hz that wait drops by more than half.

Input path. Wireless mice and keyboards can add a few milliseconds over wired ones, phone touchscreens need time to register a touch, and the browser's own event handling stacks on top.

Which means the same person getting different numbers on a phone and a PC is expected. What matters is not the absolute value but the trend within one setup.

3. What actually moves the needle

• Sleep. The biggest variable. Short sleep slows you down and, more tellingly, widens your spread — some attempts fast, some suddenly terrible.
• Age. Peaks in the early twenties and declines gradually. Individual variation is larger than the age gap, though.
• Caffeine. Can help briefly through alertness, but too much brings jitter and premature clicks.
• Practice. Raw reaction barely changes; what improves is anticipation and readiness. A lot of what makes esports players look fast is knowing what is coming, not faster nerves.

4. What 0.1 seconds means behind the wheel

Driving is where reaction time stops being trivia. The math is simple.

100km/h is 27.8 meters per second. If it takes you 0.25 seconds to hit the brake, the car covers about 6.9 meters in that time — roughly one and a half car lengths.

Real driving is far slower than a test, though. A test only asks you to press when a signal appears; on the road you first have to notice a hazard and decide. Highway design typically assumes 1.5 seconds or more for perception and reaction — about 41.7 meters at 100km/h, before braking distance even starts.

5. How to measure it honestly

• Take 5+ attempts and use the average. A single result is half luck.
• Watch your spread, not your best. Bouncing between 180ms and 400ms means poor condition even if the average looks fine.
• Keep the device and posture constant. Comparing a phone score to a desktop score tells you nothing.
• Do not pre-press. Guessing ahead improves the number but turns measurement into gambling.

Try it yourself with the reaction time test. For a different flavor of quickness, there is 1 to 50, where you tap numbers in order, and 10 seconds, where you stop a hidden timer by feel.

Summary

• Simple human reaction typically lands at 200–250ms; sub-200 usually means anticipation
• The displayed number includes display lag (about 8ms at 60Hz) and input delay
• So changes within the same setup matter more than the absolute figure
• At 100km/h, 0.25 seconds is about 6.9 meters — and real driving needs 1.5 seconds or more for perception
• The score you get after a full night's sleep is your real one