Enter the total distance and total time traveled into the calculator to determine the average car speed.

## Car Speed Formula

The following formula is used to calculate the speed of a car.

S = D/T

- Where S is the car speed
- D is the total distance
- T is the total time

## Car Speed Definition

**What is car speed? **Car speed is defined as the velocity of a moving vehicle. It is typically calculated by dividing the total distance by total time.

## Example Problem

How to calculate car speed?

**First, determine the distance.**For this example, the car was in a drag race of a quarter-mile = .25 miles.

**Next, determine the time.**The car completed the quarter mile drag race in 12 seconds.

**Finally, calculate the average speed.**Using the formula above, the average speed is calculated to be .25/(12/60/60) = 75 mph. In this problem, the 12 seconds is converted to hours by dividing by 60 twice.

## About Car Speed

**Will cars of speed limiters? **Most cars do have a speed limiter built into their framework. This is to protect the car from any potential damage that can occur at maximum speeds and RPMs.

**How accurate are car speedometers? **On modern cars, speedometers are usually accurate to +/- 1-3 mph. Over time as the car and sensors wear down, this accuracy could drop.

**What determines **car speed? A car’s speed is determined by many factors; the engine output or in other words the amount of power the engine can produce, the weight of the car, the aerodynamics, the wheel size and type, gear and transmission ratios, and more.