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.

True airspeed relative to dry air; wind is excluded. Sea-level mode assumes 15ยฐC. Constant-property ideal-gas estimate.

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 340.294 m/s โ‰ˆ 761.216 mph.
  • Constants: ฮณ = 1.4 (dry air), R โ‰ˆ 287.05287 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 geopotential-altitude temperature model: โˆ’6.5 K/km to 11 km, then 216.65 K to 20 km.

Mach to mph Conversion Table

Mach to mph (Standard Atmosphere, 15ยฐC)
Mach mph
0.176.122
0.2152.243
0.3228.365
0.4304.486
0.5380.608
0.6456.730
0.7532.851
0.8608.973
0.9685.094
1761.216
1.2913.459
1.51,141.824
21,522.432
2.51,903.040
32,283.648
43,044.864
53,806.080
* Assumes sea-level ISA at 15ยฐC: Mach 1 โ‰ˆ 761.216 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 761.216, so mph โ‰ˆ 761.216 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— 761.216.

mph = 2.3 ร— 761.216 โ‰ˆ 1,750.797 mph