Safety Calculator
Braking Distance Calculator
Calculate total stopping distance — reaction distance plus braking distance — at any speed and road condition. Results may surprise you.
Parameters
Average sober driver: 1.5s. Distracted: 2.5–3.0s.
Total Stopping Distance
at 60 mph on dry road
Reaction Distance
132 ft
Braking Distance
183 ft
In Meters
55.8 m
Car Lengths (~15 ft)
12 cars
All Conditions at 60 mph
The physics of stopping.
(ft) = (mph × 1.467) × seconds
Braking Distance = v² / (2 × μ × g)
v = speed in ft/s · μ = friction coefficient
g = 32.174 ft/s² (gravity)
Total = Reaction Distance + Braking Distance
How does speed affect stopping distance?
Stopping distance scales with the square of speed. Double your speed and braking distance quadruples. At 30 mph you stop in ~75 ft on dry road; at 60 mph it's ~183 ft — not double, but more than double.
How much does wet road increase stopping distance?
Wet roads reduce friction coefficient from ~0.8 to ~0.5, increasing braking distance by 60%. Snow cuts it to 0.25 (3× the dry distance). Black ice (μ≈0.1) can require 8× the dry braking distance.
Does ABS help stopping distance?
ABS prevents wheel lockup (which reduces friction), allowing you to steer while braking. On dry pavement, ABS doesn't significantly shorten stopping distance. On slippery surfaces, ABS can improve stopping distance by 5–20% while maintaining steering control.