Stopping Distance
Calculator
Results
- Total stopping distance (m)
- 76.953906
- Reaction distance (m)
- 27.777777
- Braking distance (m)
- 49.176129
- Total stopping distance (ft)
- 252.473447
Results
| Total stopping distance (m) | 76.953906 |
| Reaction distance (m) | 27.777777 |
| Braking distance (m) | 49.176129 |
| Total stopping distance (ft) | 252.473447 |
formula-map diagram
- Total stopping distance (m)
- 76.953906
- Reaction distance (m)
- 27.777777
- Braking distance (m)
- 49.176129
- Total stopping distance (ft)
- 252.473447
Formula breakdown
Formula
d = v × t_reaction + v² ÷ (2 × μ × g)= 76.953906875865
Note
Simplified model: results use idealised textbook relationships and ignore real-world factors such as driving style, load, temperature, aerodynamic and rolling losses, drivetrain efficiency, tyre and brake condition and road surface. CO2 figures are tailpipe only, based on the standard 2.31 kg CO2 per litre of petrol (2.68 kg per litre of diesel), and exclude fuel production and distribution. Use them as estimates, not as legal, safety or load-rating figures.
More in Automotive and transport
See all →Frequently asked questions
What is stopping distance and what two components make it up?+
Stopping distance is the total distance a vehicle travels from the moment a driver perceives a hazard to when the vehicle comes to a complete stop. It combines reaction distance (traveled during the driver's reaction time, before braking starts) and braking distance (traveled while the brakes are actively slowing the vehicle).
How is reaction distance calculated?+
Reaction distance = speed × reaction time. For example, at 60 mph (88 ft/s) with a typical 1.5-second reaction time, the vehicle travels about 132 feet before the driver even begins braking — this portion depends only on speed and reaction time, not on the brakes at all.
Why does stopping distance increase faster than speed as you go faster?+
Reaction distance scales linearly with speed, but braking distance scales with speed squared, so total stopping distance grows faster than speed alone would suggest. This compounding effect is why small increases in speed, especially at higher speeds, produce noticeably larger increases in total stopping distance.
What's a common misconception about reaction time?+
People often assume their reaction time is near-instant, but the commonly used average of about 1.5 seconds already reflects an alert driver in good conditions — fatigue, distraction (especially phone use), and alcohol can roughly double or triple actual reaction time, dramatically increasing the reaction-distance portion of the total.
Why is stopping distance a better real-world safety figure than braking distance alone?+
Braking distance alone ignores the very real distance covered before the driver even reacts, which in normal driving is often comparable to or larger than the braking distance itself at typical road speeds. Stopping distance gives a more complete and realistic picture of the total space needed to avoid a hazard.