# Mach Number to Speed Of Light Conversion

Enter the Mach number below to convert the speed to speed of light.

**Results in Speed Of Light:**

## How to Convert Mach Number to Speed Of Light

To convert a Mach measurement to a speed of light measurement, multiply the Mach number by the conversion ratio. Mach 1 is equal to 1.1441E-6 speed of light, so use this simple formula to convert:

The speed in speed of light is equal to the Mach number multiplied by 1.1441E-6.

**For example,**here's how to convert Mach 2 to speed of light using the formula above.

Mach number and speed of light are both units used to measure speed. Keep reading to learn more about each unit of measure.

## Mach Number

Mach, sometimes also referred to as a Mach number, is the ratio of the speed of an object to the speed of sound.^{[1]}

Mach can be abbreviated as M, and is also sometimes abbreviated as Ma. For example, Mach 1 can be written as 1 M or 1 Ma.

Although Mach can be abbreviated *M* or *Ma*, the Mach number is typically expressed with the number after the unit name.
For example, the expression *Mach 3* is preferred rather than *3 Machs* or *3 M*.

The speed is classified as either subsonic, transonic, supersonic, or hypersonic depending on the Mach number.

Speed Classification | Mach Number |
---|---|

Subsonic | Mach < 1.0 |

Transonic | Mach = 1.0 |

Supersonic | Mach > 1.0 |

Hypersonic | Mach > 5.0 |

## Speed Of Light

The speed of light is equal to exactly 299,792,458 meters per second, or 670,616,629 miles per hour.
The definition of the speed of light is actually derived from the most recent 1983 international definition of the meter.^{[2]}

Speed of light can be abbreviated as *c*; for example, 1 speed of light can be written as 1 c.

## Mach to Speed Of Light Conversion Table

Mach Number | Speed Of Light |
---|---|

1 M | 0.0000011441 c |

2 M | 0.0000022882 c |

3 M | 0.0000034324 c |

4 M | 0.0000045765 c |

5 M | 0.0000057206 c |

6 M | 0.0000068647 c |

7 M | 0.0000080089 c |

8 M | 0.000009153 c |

9 M | 0.000010297 c |

10 M | 0.000011441 c |

100 M | 0.000114 c |

1,000 M | 0.001144 c |

10,000 M | 0.011441 c |

100,000 M | 0.114412 c |

1,000,000 M | 1.1441 c |

## References

- NASA, Mach Number, https://www.grc.nasa.gov/WWW/BGH/mach.html
- National Institute of Standards and Technology, SI Redefinition: Meter, https://www.nist.gov/si-redefinition/meter