Braking Distance Calculator
Fill in the values and the answer updates as you type.
How the Braking Distance Calculator works
Reaction distance = speed × reaction time. Braking distance = v² ÷ (2 × friction × 9.81). Friction values are typical approximations; real distances depend on tires, brakes, and slope. Example: with Speed 80 km/h, Reaction time 1.5 s, and Road surface Dry asphalt, the result is Total stopping distance (m) = 69.3; Reaction distance (m) = 33.3; Braking distance (m) = 36.
Inputs and results
The Braking Distance Calculator takes 3 inputs and gives 3 results.
What you enter
- Speed (km/h) — starts at 80.
- Reaction time (s) — starts at 1.5.
- Road surface — starts at Dry asphalt. Choose from: Dry asphalt, Wet asphalt, Snow and Ice.
What you get
- Total stopping distance (m)
- Reaction distance (m)
- Braking distance (m)
Example: Braking Distance Calculator with the starting values
With speed 80 km/h, reaction time 1.5 s and road surface Dry asphalt, the calculator returns:
| Total stopping distance (m) | 69.3 |
|---|---|
| Reaction distance (m) | 33.3 |
| Braking distance (m) | 36 |
Change any value above and the results update straight away.
Braking Distance Calculator FAQ
How do I use the Braking Distance Calculator?
Enter speed, reaction time and road surface in the fields, then read total stopping distance (m), reaction distance (m) and braking distance (m) in the result panel. The answer updates as you type, and you can press Calculate or Enter to refresh it. Use “Copy link” to share your exact numbers with someone else.
What does the Braking Distance Calculator calculate?
Reaction and braking distance at a given speed. It returns total stopping distance (m), reaction distance (m) and braking distance (m) from the 3 values you provide.
What values does the Braking Distance Calculator start with?
It opens with speed 80 km/h, reaction time 1.5 s and road surface Dry asphalt so you can see a working result straight away. Replace them with your own numbers, or press Reset to return to these starting values.
Is the Braking Distance Calculator free and private?
Yes. It is free, needs no account, and runs in your browser, so nothing you type is sent to or stored on our servers. See the Privacy Policy for details.
Can I rely on the Braking Distance Calculator for important decisions?
Treat the result as a well-rounded estimate. Real situations often have details a general calculator cannot know, so confirm important decisions with a qualified professional. See the Disclaimer for more.