UK Stopping Distances Explained (and How to Memorise Them)
4 May 2026·5 min read·By TheoryDrive Editors
Thinking distance, braking distance and total stopping distance — what they mean, when they appear in the test, and a trick to remember the numbers.
Stopping distance questions come up in almost every theory test. Examiners want to know you understand the relationship between speed, reaction time and braking — not just that you have memorised a table.
The three components
- Thinking distance: how far you travel from spotting a hazard to pressing the brake. Roughly one foot per mph in good conditions.
- Braking distance: how far the car travels after the brakes are applied. Increases with the square of speed — doubling speed quadruples braking distance.
- Total stopping distance: thinking + braking, in metres.
The official numbers
- 20 mph — 12 metres (3 car lengths)
- 30 mph — 23 metres (6 car lengths)
- 40 mph — 36 metres (9 car lengths)
- 50 mph — 53 metres (13 car lengths)
- 60 mph — 73 metres (18 car lengths)
- 70 mph — 96 metres (24 car lengths)
A memory trick
Start with 20 mph = 12m. Then add 9, 13, 17, 20, 23 metres as you step up in 10 mph increments. The gaps grow because braking distance scales non-linearly with speed.
Wet and icy conditions
Double stopping distances in the wet. In ice, multiply by ten. Tyre tread and brake condition matter too — bald tyres in the rain can extend stopping distance beyond even the icy multiplier.