Enter the speed (mph) and the reaction time (ms) into the Reaction Distance Calculator. The calculator will evaluate and display the Reaction Distance.

## Reaction Distance Formula

The following formula is used to calculate the Reaction Distance.

Dreact = S*5280/3600 * T/1000

• Where Dreact is the Reaction Distance (ft)
• S is the speed (mph)
• T is the reaction time (ms)

## How to Calculate Reaction Distance?

The following example problems outline how to calculate Reaction Distance.

Example Problem #1:

1. First, determine the speed (mph).
• The speed (mph) is given as: 60.
2. Next, determine the reaction time (ms).
• The reaction time (ms) is provided as: 500.
3. Finally, calculate the Reaction Distance using the equation above:

Dreact = S*5280/3600 * T/1000

The values given above are inserted into the equation below and the solution is calculated:

Dreact = 60*5280/3600 * 500/1000 = 44 (ft)

Example Problem #2:

For this problem, the variables needed are provided below:

speed (mph) = 70

reaction time (ms) = 350

This example problem is a test of your knowledge on the subject. Use the calculator above to check your answer.

Dreact = S*5280/3600 * T/1000 = ?