# Speed Conversion: Convert mi/s to km/s, km/s to mi/s

Use the **online** conversion calculators to convert between miles per second (mi/s) and kilometers per second (km/s).

## Conversion Calculators

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

## Convert mi/s to km/s

## Convert km/s to mi/s

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

**How to convert km/s to mi/s** Use the conversion calculator on the right-hand side titled "Convert km/s to mi/s". Enter a value in the km/s field and click on the "Calculate mi/s" button. Your answer will appear in the mi/s field.

## Definitions

Below are definitions relating to these conversion formulas:

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

inches per second | in/s | US Customary Units (and Imperial) | |

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

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

miles per second | mi/s | US Customary Units (and Imperial) | 1 mi/s = 1760 yd/s 1 mi/s = 5280 ft/s |

millimeters per second | mm/s | Metric System | 1000 mm/s = 1 m/s |

centimeters per second | cm/s | Metric System | 100 cm/s = 1 m/s 1 cm/s = 10 mm/s |

decimeters per second | dm/s | Metric System | 10 dm/s = 1 m/s 1 dm/s = 10 cm/s |

meters per second | m/s | Metric System | 1 m/s = 1000 mm/s 1 m/s = 100 cm/s 1 m/s = 10 dm/s |

kilometers per second | km/s | Metric System | 1 km/s = 1000 m/s |