UK Stopping Distances for the Theory Test: Chart, Car Lengths and an Easy Way to Remember

Stopping distances come up in almost every theory test, usually as "What is the shortest overall stopping distance at 40 mph?" They are easy marks once you know the numbers, and they are worth understanding properly because they explain why speed limits and following gaps are set where they are.

I build RoadTick: Driving Theory Test, a free UK theory test app for iPhone and iPad, and the screenshots in this guide come from it. If you want to practise as you read, get RoadTick on the App Store.

What are the UK stopping distances?

These are the typical stopping distances for a car in good conditions, from the Highway Code:

Speed	Thinking	Braking	Overall	Car lengths
20 mph	6 m	6 m	12 m (40 ft)	3
30 mph	9 m	14 m	23 m (75 ft)	6
40 mph	12 m	24 m	36 m (118 ft)	9
50 mph	15 m	38 m	53 m (175 ft)	13
60 mph	18 m	55 m	73 m (240 ft)	18
70 mph	21 m	75 m	96 m (315 ft)	24

The car lengths assume an average car of about 4 metres.

What is the difference between thinking and braking distance?

• Thinking distance is how far you travel between seeing a hazard and pressing the brake. It grows in a straight line with speed: 3 m for every 10 mph.
• Braking distance is how far you travel once the brakes are on. It grows much faster: doubling your speed roughly quadruples it. That is why going from 30 to 60 mph more than triples the overall distance.

Thinking distance gets longer if you are tired, distracted, ill, or have taken alcohol or drugs. Braking distance gets longer on wet, icy or loose surfaces, going downhill, with worn tyres or brakes, or with a heavy load.

How do I remember stopping distances?

Two tricks make the table easy:

1. Thinking distance: take the first digit of the speed and multiply by 3. 30 mph gives 9 m, 70 mph gives 21 m.
2. Overall distance in feet: multiply the speed by 2, 2.5, 3, 3.5, 4 and 4.5 for 20 to 70 mph. 30 × 2.5 = 75 ft, 70 × 4.5 = 315 ft. Then convert using the table if the question asks for metres.

For the theory test itself, most people simply memorise the overall column in metres: 12, 23, 36, 53, 73, 96.

How much longer are stopping distances in rain and ice?

Conditions	Stopping distance	At 70 mph
Dry	As in the table	96 m
Wet	Up to 2 times longer	Up to about 192 m
Icy	Up to 10 times longer	Up to about 960 m

In fog, keep a gap that lets you stop within the distance you can see clearly.

How big a gap should I leave?

The Highway Code says leave at least a two-second gap behind the vehicle in front on roads with faster traffic, and at least four seconds on wet roads. Pick a fixed point, such as a lamp post. When the car ahead passes it, say "Only a fool breaks the two-second rule". If you reach the point before you finish, you are too close. In ice and snow the gap may need to be up to ten times greater.

Which stopping distance questions appear in the theory test?

• The overall stopping distance at a given speed, usually 30, 40, 50 or 70 mph.
• How much longer stopping distances are on wet or icy roads.
• The two-second rule and how it changes in the wet.
• What increases thinking distance (tiredness, alcohol, distraction).

More of the numbers the test likes are in how to revise the Highway Code, and how to use mocks to lock them in is in driving theory mock test strategy.

How RoadTick helps

• Practice questions for every theory topic, each with a plain-English explanation.
• Timed mock tests in the real format: 50 questions in 57 minutes, scored against the pass mark of 43.
• Hazard perception practice to build the timing the second part tests.
• The Highway Code broken into short sections that are easy to revise.
• UK road signs and markings with clear images and meanings.
• Progress tracking that shows which topics still need work before you book.

Download RoadTick free on the App Store and turn spare minutes into theory test practice. RoadTick is an independent app and is not affiliated with the DVSA.