Convert Knots to Mach Number

Enter the speed in knots below to get the value converted to Mach number.

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1 kn = Mach 0.0015

How to Convert Knots to Mach Number

Speedometers are used in vehicles to measure speed

To convert a knot measurement to a Mach measurement, multiply the speed by the conversion ratio. One knot is equal to Mach 0.0015, so use this simple formula to convert:

Mach number = knots × 0.0015

The Mach number is equal to the speed in knots multiplied by 0.0015.

For example, here's how to convert 5 knots to Mach number using the formula above.
5 kn = (5 × 0.0015) = Mach 0.007499

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

Knots

One knot is equal to a speed of one nautical mile per hour,[1] 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 Number

Mach, sometimes also referred to as a Mach number, is the ratio of the speed of an object to the speed of sound.[2]

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

Knot to Mach Conversion Table

Mach numbers converted to Mach number
Knots Mach Number
166.68 kn Mach 0.25
333.37 kn Mach 0.5
500.05 kn Mach 0.75
666.74 kn Mach 1
1,000 kn Mach 1.5
1,333 kn Mach 2
1,667 kn Mach 2.5
2,000 kn Mach 3
2,334 kn Mach 3.5
2,667 kn Mach 4
3,000 kn Mach 4.5
3,334 kn Mach 5
3,667 kn Mach 5.5
4,000 kn Mach 6
4,334 kn Mach 6.5
4,667 kn Mach 7
5,001 kn Mach 7.5
5,334 kn Mach 8
5,667 kn Mach 8.5
6,001 kn Mach 9
6,334 kn Mach 9.5
6,667 kn Mach 10

References

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