Mach to MPH Converter
Convert Mach number to miles per hour at sea level and 15 °C. Results update as you type; exact factors shown.
One Mach (sea level, 15 °C) is 761.2071 miles per hour — see the exact factor, not a rounded rule of thumb.
How the mach to mph converter works
Speeds convert through metres per second. 1 km/h is 1000/3600 m/s; 1 mph is 1609.344/3600 m/s; a knot is one nautical mile (1,852 m) per hour. Mach is shown against the standard sea-level speed of sound of 340.29 m/s and varies with altitude and temperature.
The UK is metric for most trade and science but keeps miles, pints, stone and mpg (with the imperial gallon) in daily life.
Common speed conversions
| From | To | Units |
|---|---|---|
| 0.1 Ma | 76.1207 mph | Mach (sea level, 15 °C) to miles per hour |
| 0.25 Ma | 190.3018 mph | Mach (sea level, 15 °C) to miles per hour |
| 0.5 Ma | 380.6035 mph | Mach (sea level, 15 °C) to miles per hour |
| 0.8 Ma | 608.9656 mph | Mach (sea level, 15 °C) to miles per hour |
| 0.85 Ma | 647.026 mph | Mach (sea level, 15 °C) to miles per hour |
| 1 Ma | 761.2071 mph | Mach (sea level, 15 °C) to miles per hour |
| 1.5 Ma | 1,141.8106 mph | Mach (sea level, 15 °C) to miles per hour |
| 2 Ma | 1,522.4141 mph | Mach (sea level, 15 °C) to miles per hour |
| 2.5 Ma | 1,903.0176 mph | Mach (sea level, 15 °C) to miles per hour |
| 3 Ma | 2,283.6212 mph | Mach (sea level, 15 °C) to miles per hour |
| 5 Ma | 3,806.0353 mph | Mach (sea level, 15 °C) to miles per hour |
| 10 Ma | 7,612.0705 mph | Mach (sea level, 15 °C) to miles per hour |
Units in this converter and their exact factors
| Unit | Symbol | One unit in metre per seconds |
|---|---|---|
| metre per second | m/s | 1 metre per second |
| kilometre per hour | km/h | 0.2777777778 metre per second |
| mile per hour | mph | 0.44704 metre per second |
| knot | kn | 0.5144444444 metre per second |
| foot per second | ft/s | 0.3048 metre per second |
| Mach (sea level, 15 °C) | Ma | 340.29 metre per second |
FAQFrequently asked questions about speed conversion
What is Mach 1 in mph?
About 761 mph at sea level and 15 °C.
Does Mach 1 change with altitude?
Yes — the speed of sound depends on air temperature, so at cruise altitude Mach 1 is nearer 660 mph.
What Mach does an airliner cruise at?
Around Mach 0.78 to 0.85.
What was Concorde's speed?
Mach 2.04, about 1,354 mph at altitude.
What is Mach 2 at sea level?
About 1,522 mph.
Where these figures come from
- BIPM — The International System of Units (SI Brochure, 9th edition) — definitions of the base and derived units.
- NIST Special Publication 811 — Guide for the Use of the International System of Units — the exact conversion factors used here.
- National Physical Laboratory (NPL) — United Kingdom's national measurement authority.
Last checked: September 2026. Conversion factors are fixed by definition and do not change with tax years or regulations.