Convert Mach to mph or reverse-convert a speed to Mach using standard or custom static air temperature, with knots, km/h, m/s, and regime details.

All visible numeric inputs are required unless labeled optional.

Mach to Mph Formula

The following formulas convert between Mach and speed using the local speed of sound determined by the chosen environment.

v = M ร— a where a = โˆš(ฮณ R T)
  • Standard sea-level (15ยฐC) speed of sound: a โ‰ˆ 340.3 m/s โ‰ˆ 761.207 mph.
  • Constants: ฮณ = 1.4 (dry air), R = 287.05 J/(kgยทK); temperature T in kelvin.
  • Unit links: 1 m/s = 2.236936 mph; 1 km/h = 0.621371 mph; 1 kn = 1.150779 mph.
  • ISA temperature model: -6.5 K/km to 11 km, then isothermal to 20 km.

Mach to Mph Conversion Table

Mach to mph (Standard Atmosphere, 15ยฐC)
Mach mph
0.176.121
0.2152.241
0.3228.362
0.4304.483
0.5380.604
0.6456.724
0.7532.845
0.8608.966
0.9685.086
1761.207
1.2913.448
1.51,141.811
21,522.414
2.51,903.018
32,283.621
43,044.828
53,806.035
* Assumes sea-level ISA at 15ยฐC: Mach 1 โ‰ˆ 761.207 mph.

How do you convert Mach to mph? Multiply Mach by the local speed of sound in mph: mph = Mach ร— a_mph; at sea level (15ยฐC), a_mph โ‰ˆ 761.207, so mph โ‰ˆ 761.207 ร— Mach.

How do you convert mph to Mach? Divide mph by the local speed of sound in mph: Mach = mph รท a_mph; choose Standard, Custom Temperature, or Altitude (ISA) to set a_mph.

Example Problem

Convert Mach 2.3 at sea level (15ยฐC) to mph.

Use the seaโ€‘level relation: mph = Mach ร— 761.207.

mph = 2.3 ร— 761.207 โ‰ˆ 1,750.776 mph