Tools · Mach to MPH
Mach to MPH Converter
Enter a Mach number, see the equivalent in miles per hour. Uses the sea-level speed of sound, the standard reference for the sound barrier, fighter jets, and spacecraft reentry figures.
Mach 1 = 767.269 mph at sea level, ~20°C (speed of sound 343 m/s)
Why Mach is not a fixed speed
Mach number is a ratio, not a fixed velocity: it is your speed divided by the local speed of sound. The speed of sound depends almost entirely on air temperature, which falls as you climb. At sea level on a mild day it is about 767 mph (343 m/s). At an airliner's cruising altitude of 35,000 feet, where the air is roughly −55°C, the speed of sound drops to around 660 mph — so the same Mach 0.85 cruise is a lower ground speed than the sea-level math suggests.
This converter uses the sea-level reference because that is the number quoted for the sound barrier and most published Mach figures. Chuck Yeager broke Mach 1 in 1947. Concorde cruised at Mach 2 (about 1,350 mph). The SR-71 Blackbird held Mach 3.2. Spacecraft reentry peaks near Mach 25. For a temperature-accurate figure at a specific altitude, use the speed of sound calculator.
Mach to MPH reference (sea level)
| Mach | MPH |
|---|---|
| 0.5 | 384 |
| 0.8 | 614 |
| 0.9 | 691 |
| 1 | 767 |
| 1.2 | 921 |
| 1.5 | 1,151 |
| 2 | 1,535 |
| 2.5 | 1,918 |
| 3 | 2,302 |
| 3.2 | 2,455 |
| 5 | 3,836 |
| 10 | 7,673 |
Related converters
- Speed of sound calculator — Mach 1 at any altitude and temperature.
- FPS to MPH — feet per second to miles per hour.
- Knots to MPH — the aviation and marine speed unit.
- Live GPS speedometer — read your real speed in the browser.