Enter speed, reaction time, and road condition, then click Calculate.

The stopping distance of a vehicle is the total distance traveled from the moment a hazard is perceived to the moment the vehicle comes to a complete stop. It consists of two components: reaction distance (distance traveled during the driver's reaction time) and braking distance (distance traveled while braking). The reaction distance is calculated as Reaction Distance = Speed × Reaction Time. The braking distance is determined by the physics of friction: Braking Distance = v² / (2 × μ × g), where v is speed in m/s, μ is the coefficient of friction between tires and road surface, and g is gravitational acceleration (9.81 m/s²). Road grade also affects braking: uphill reduces braking distance, downhill increases it. This calculator helps drivers understand how speed, reaction time, road conditions, and grade affect stopping distance, promoting safer driving decisions.

1. Enter the vehicle Speed in km/h.
2. Enter the driver’s Reaction Time in seconds (typical: 1.5 s).
3. Select the Road Condition (Dry, Wet, Snow, or Ice).
4. Enter the Road Grade percentage (positive = uphill, negative = downhill).
5. Click Calculate Stopping Distance to see the results.
6. The result shows reaction distance, braking distance, and total stopping distance.
7. Click Reset to restore default example values.