Theory Test Help

How to reMember Stopping Distances

Easy way remember stopping distances for your driving theory test.

What does stopping distance mean?

Stopping distance is the total distance your vehicle travels from the instant you notice a hazard to the moment the car comes to a complete stop. It consists of two parts:

  • Thinking distance: How far you travel while your brain clocks the danger and your foot moves to the brake.
  • Braking distance: How far you travel after the brakes are applied until the car stops.
Thinking Distance 9 Metres (30 Feet)
Braking Distance 14 Metres (45 Feet)
Total Stopping Distance: 23 Metres (75 Feet)

Typical Stopping Distances

Average car length = 4 metres (13 feet)

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

The distances shown are a general guide. The distance will depend on your attention (thinking distance), the road surface, the weather conditions and the condition of your vehicle.

Theory Test Guide: Stopping Distance

You don't need to memorise every number in the Highway Code. Use the Multiply Method: Start at 2 (for 20mph) and add 0.5 for every 10mph increase.

💡 Instructor Hint: Thinking distance is ALWAYS just your speed in feet. For example, 30mph = 30ft thinking distance.

Multiplier Table

SpeedMultiplierTotal
20 mphx 240 ft
30 mphx 2.575 ft
40 mphx 3120 ft
50 mphx 3.5175 ft
60 mphx 4240 ft
70 mphx 4.5315 ft

Hazardous Conditions

🌧️ Wet Roads

Stopping distance DOUBLES because tyres struggle to grip the road surface.

Distance x 2

❄️ Ice & Snow

Stopping distance can be up to 10 TIMES longer. Maintain massive gaps!

Distance x 10

⏱️ 2-Second Rule

Keep a safe gap. If the road is wet, increase this to 4 seconds; if icy, up to 20 seconds.

"Only a fool breaks the rule"

Stopping Distance Calculator

Use our interactive online stopping distance calculator to see how different speeds impact your safety on the road.

Calculate Your Distance

Enter your speed to see the math in action:

Thinking 30ft
Braking 45ft
Total Stopping Distance 75ft ~ 6 Car Lengths

Why
Understanding
Stopping
Distances
Matters

Knowing how stopping distances increase with speed is essential for safe driving. At 30 mph, the stopping distance is about 75 feet, but at 40 mph, it jumps by 45 feet—a rise of over 50%.

At 70 mph, you may need the length of a football field to stop, even in ideal conditions. In wet weather, that distance can more than double. Thinking distance—the distance your car travels before you even react—is equal to your speed in feet. That means at 40 mph, you’ve already travelled 40 feet before braking. Always leave a 2-second gap, or 4 seconds in the wet.

UK Highway Code Stopping Distances Diagram

Diagram: Thinking distance (Blue) + Braking distance (Red) = Total Stopping Distance.

The 2 Second Rule

One of the key principles for safe driving is the 2 second rule, which helps maintain safe distances on the road. In dry conditions, it is important to keep at least a 2 second gap between your vehicle and the one ahead.

💡 How to check:

"Watch when the car in front passes a fixed object, like a lamppost... mentally say 'only a fool breaks the 2 second rule' until you reach that object."

In heavy rain, repeat the phrase to create a 4 second cushion. In icy conditions, aim for a much larger gap of about 20 seconds.