Use the formula: Braking distance = (speed²) / (2 × deceleration)
Convert speed to meters per second before calculating
Measure deceleration in meters per second squared
Square the speed value
Divide by twice the deceleration value
Result is the braking distance in meters
If using mph, convert mph to m/s first
If using km/h, convert km/h to m/s first
Include road and tire conditions in the deceleration value
Use a lower deceleration value for wet, icy, or loose surfaces