Mach Number Calculator Formula

Understand the math behind the mach number calculator. Each variable explained with a worked example.

Use the Mach Number Calculator

Formulas Used

Speed of Sound

sound_speed = 331.3 + 0.606 * temperature

Mach Number

mach_number = object_speed / (331.3 + 0.606 * temperature)

Variables

VariableDescriptionDefault
object_speedObject Speed(m/s)680
temperatureAir Temperature(°C)20

How It Works

Mach Number

The Mach number is a dimensionless ratio comparing an object's speed to the speed of sound in the surrounding medium.

Formula

M = v / v_sound

  • M < 1: subsonic
  • M = 1: sonic (speed of sound)
  • M > 1: supersonic
  • M > 5: hypersonic

    • Worked Example

    An aircraft flying at 680 m/s in air at 20 degrees C.

    object_speed = 680temperature = 20
    1. 01v_sound = 331.3 + 0.606 * 20 = 343.4 m/s
    2. 02M = 680 / 343.4
    3. 03M = 1.980
    4. 04The aircraft is supersonic (M > 1)

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