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.
Australia is fully metric under the National Measurement Act 1960; imperial units appear only in trade with the US and in older documents.
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 Measurement Institute (NMI) — Australia's national measurement authority.
Last checked: September 2026. Conversion factors are fixed by definition and do not change with tax years or regulations.