# Mach Number to Knots Converter

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

## Result in Knots:

Mach 1 = 666.738661 kn

Do you want to convert knots to Mach number?

## 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:

knots = Mach number × 666.738661

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 2 = (2 × 666.738661) = 1,333.477322 kn

## What Is 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 classifications for various mach numbers.
Speed Classification Mach Number
Subsonic Mach < 1.0
Transonic Mach = 1.0
Supersonic Mach > 1.0
Hypersonic Mach > 5.0

## What Is a Knot?

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 numbers converted to knots
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

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