Unit-To-Unit Speed conversion

Mach to MPH

1 Mach number = 761.207050823 miles per hour

Mach 1 at sea level is 767 mph, but the same Mach number at 35,000 feet is only about 660 mph, because the speed of sound falls with air temperature.

Formula mph = Ma × 761.207050823193

=

Type in either field — the other updates on every keystroke. Need other units? Open the full speed converter.

Mach to MPH — quick reference
Mach (sea level)Mile per hour
1 Ma761.207051 mph
2 Ma1522.414102 mph
3 Ma2283.621152 mph
4 Ma3044.828203 mph
5 Ma3806.035254 mph
10 Ma7612.070508 mph
15 Ma11418.105762 mph
20 Ma15224.141016 mph
25 Ma19030.176271 mph
50 Ma38060.352541 mph
100 Ma76120.705082 mph
500 Ma380603.525412 mph
1000 Ma761207.050823 mph
MPH to Mach — reverse
Mile per hourMach (sea level)
1 mph0.001314 Ma
2 mph0.002627 Ma
3 mph0.003941 Ma
4 mph0.005255 Ma
5 mph0.006569 Ma
10 mph0.013137 Ma
15 mph0.019706 Ma
20 mph0.026274 Ma
25 mph0.032843 Ma
50 mph0.065685 Ma
100 mph0.13137 Ma
500 mph0.656852 Ma
1000 mph1.313703 Ma

Worked examples

Common values
SituationFromTo
Half the speed of sound0.5 Mach380.6 mph
Airliner Mach number0.8 Mach609 mph
Speed of sound1 Mach761.2 mph
Mach 22 Mach1,522 mph
Mach 33 Mach2,284 mph
Hypersonic5 Mach3,806 mph

Mental-math shortcut

Multiply by about 760 at sea level, or about 660 at airliner cruising altitude. Mach 2 is roughly 1,520 mph at sea level.

Where this conversion comes up

Aircraft speeds are quoted as Mach numbers. An airliner flying at Mach 0.85 at 35,000 ft is doing about 560 mph.

Common mistakes

Mach is not a fixed speed, because sound travels slower in cold air. The table uses the standard sea-level figure of 761.2 mph.

Background

The unit honours the Austrian physicist Ernst Mach. Chuck Yeager first passed Mach 1 in level flight in the Bell X-1 on 14 October 1947.

Frequently asked

How many miles per hour are in a Mach number?
1 Mach number = 761.207050823 miles per hour. In the other direction, 1 mile per hour = 0.001313703 Mach.
What is a Mach number?
Mach is a ratio to the local speed of sound, not a fixed speed. This page uses 340.29 m/s, the value in dry air at sea level and 15 °C; it falls with altitude.
What is a mile per hour?
Miles per hour is the road speed unit in the United States and the United Kingdom, and the conventional unit for wind speed in US forecasts.
How many mph is Mach 1?
About 761 mph at sea level, but only about 660 mph at airliner cruising altitude.

Related speed conversions

MPH to KM/H KM/H to MPH Knots to MPH Knots to KM/H Metres per Second to KM/H MPH to Metres per Second