# Speed Converter

## Speed Converter Calculators

Regardless of the direction of movement, speed is the rate at which an object's position changes. Speed in a direction is defined as velocity. If you go forward or backwards at 2 metres per second, your speed is exactly 2 m/s. Imagine you were moving back while still moving forward; your velocity would be negative 2 m/s.

Illustrates the distinction between velocity and speed. While velocity affects the direction, speed does not.

Although kilometres per hour (km/h) is occasionally used when measuring the speed of vehicles, for most science applications, metres per second (m/s) is the SI unit for speed and velocity. While marine vessels traditionally use knots or nautical miles per hour, the English system commonly expresses speed as miles per hour (mph) or occasionally feet per second (ft/s).

## How fast is it?

Without considering the direction of travel, an object's speed is defined as the distance it travels in a given time. Vectors or positive and negative numbers are used in the related term velocity to denote direction.

## Units of velocity

Some of the units listed in this speed conversion calculator might be unfamiliar. In nations that use the imperial system, like the United States, the United Kingdom, and Australia, the units of feet per second and miles per hour are frequently used. On the other hand, countries that use the metric system, or the rest of the world, prefer metres per second and kilometres per hour as their preferred units.

Knots are the ideal unit to use if you intend to sail the high seas (they are used regardless of your affiliation to the imperial or metric systems). One nautical mile per hour equals one knot (approximately 1.151 mph).

## How do you change the speed units?

### Conversion of Speeds

Simply multiplying the speed by the appropriate conversion factor will convert the one-speed unit to another. The equation form is as follows:

**conversion factor * original speed Equals converted speed**

Therefore, we need a conversion factor of 1.609344, for instance, to convert from mph to kmh (miles per hour to kilometres per hour). Let's try converting 200 mph to kilometres per hour:

**300 km/h is equal to 200 mph multiplied by 1.609344.**

The conversion factor for converting metres per second to miles per hour is 2.23693629. This is another example. Let's demonstrate this using Usain Bolt's record-breaking 100-meter time of 8.70 seconds. 100 metres divided by 8.70 seconds results in a speed of 11.5 m/s. The following provides the conversion to mph:

**11.5 m/s * 2.23693629 25.7 mph is the speed in mph.**