# Mach Number to Knots Conversion

Enter the Mach number below to convert the speed to knots.

**Results in Knots:**

## How to Convert Mach Number to Knots

To convert a Mach measurement to a knot measurement, multiply the Mach number by the conversion ratio. Mach 1 is equal to 666.738661 knots, so use this simple formula to convert:

The speed in knots is equal to the Mach number multiplied by 666.738661.

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

Mach number and knots 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 |

## Knots

One knot is equal to a speed of one nautical mile per hour,^{[2]} or one minute of latitude per hour.

Knots can be abbreviated as *kn*, and are also sometimes abbreviated as *kt*. For example, 1 knot can be written as 1 kn or 1 kt.

## Mach to Knot Conversion Table

Mach Number | Knots |
---|---|

Mach 0.25 | 166.68 kn |

Mach 0.5 | 333.37 kn |

Mach 0.75 | 500.05 kn |

Mach 1 | 666.74 kn |

Mach 1.5 | 1,000 kn |

Mach 2 | 1,333 kn |

Mach 2.5 | 1,667 kn |

Mach 3 | 2,000 kn |

Mach 3.5 | 2,334 kn |

Mach 4 | 2,667 kn |

Mach 4.5 | 3,000 kn |

Mach 5 | 3,334 kn |

Mach 5.5 | 3,667 kn |

Mach 6 | 4,000 kn |

Mach 6.5 | 4,334 kn |

Mach 7 | 4,667 kn |

Mach 7.5 | 5,001 kn |

Mach 8 | 5,334 kn |

Mach 8.5 | 5,667 kn |

Mach 9 | 6,001 kn |

Mach 9.5 | 6,334 kn |

Mach 10 | 6,667 kn |

## References

- NASA, Mach Number, https://www.grc.nasa.gov/WWW/BGH/mach.html
- NASA, Knots Versus Miles per Hour, https://www.grc.nasa.gov/WWW/K-12/WindTunnel/Activities/knots_vs_mph.html