# Convert mph to km/h, km/h to mph - Speed Conversion

Use these **online** calculators to convert between miles per hour (mph) and kilometers per hour (km/h). These Speed conversion calculators provide a quick and easy way to convert:

- mph to km/h
- km/h to mph

## Conversion Calculators

Enter your value in one of the conversion calculators below to **convert mph to km/h** or **convert km/h to mph**.

## Convert mph to km/h

## Convert km/h to mph

**How to convert mph to km/h**: Use the conversion calculator on the left titled "Convert mph to km/h". Enter a value in the mph field and click on the "Calculate km/h" button. Your answer will appear in the km/h field.

**How to convert km/h to mph**: Use the conversion calculator on the right titled "Convert km/h to mph". Enter a value in the km/h field and click on the "Calculate mph" button. Your answer will appear in the mph field.

## Conversion Definitions

The following is a list of definitions relating to conversions between miles per hour and kilometers per hour.

### What are miles per hour (mph)?

Miles per hour is a unit of speed in both US Customary Units as well as the Imperial System. It measures the number of miles travelled in an hour. The symbol for miles per hour is mph.

### What are kilometers per hour (km/h)?

Kilometers per hour is a unit of speed in the Metric System. It measures the number of kilometers travelled in an hour. The symbol for kilometers per hour is km/h and the International spelling is kilometres per hour.

### Understanding the Speed Units

This table provides a summary of the Speed units within their respective measurement systems.

Unit | Symbol | Measurement System | Description |
---|---|---|---|

inches per hour | in/h | US Customary Units (and Imperial) | |

feet per hour | ft/h | US Customary Units (and Imperial) | 1 ft/h = 12 in/h |

yards per hour | yd/h | US Customary Units (and Imperial) | 1 yd/h = 3 ft/h |

miles per hour | mph | US Customary Units (and Imperial) | 1 mph = 1760 yd/h 1 mph = 5280 ft/h |

millimeters per hour | mm/h | Metric System | 1000 mm/h = 1 m/h |

centimeters per hour | cm/h | Metric System | 100 cm/h = 1 m/h 1 cm/h = 10 mm/h |

decimeters per hour | dm/h | Metric System | 10 dm/h = 1 m/h 1 dm/h = 10 cm/h |

meters per hour | m/h | Metric System | 1 m/h = 1000 mm/h 1 m/h = 100 cm/h 1 m/h = 10 dm/h |

kilometers per hour | km/h | Metric System | 1 km/h = 1000 m/h |