Mach to Metres per Second Converter
Convert Mach number to metres per second at sea level and 15 °C. Results update as you type; exact factors shown.
One Mach (sea level, 15 °C) is 340.29 metres per second — see the exact factor, not a rounded rule of thumb.
How the mach to metres per second 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 | 34.029 m/s | Mach (sea level, 15 °C) to metres per second |
| 0.25 Ma | 85.0725 m/s | Mach (sea level, 15 °C) to metres per second |
| 0.5 Ma | 170.145 m/s | Mach (sea level, 15 °C) to metres per second |
| 0.8 Ma | 272.232 m/s | Mach (sea level, 15 °C) to metres per second |
| 0.85 Ma | 289.2465 m/s | Mach (sea level, 15 °C) to metres per second |
| 1 Ma | 340.29 m/s | Mach (sea level, 15 °C) to metres per second |
| 1.5 Ma | 510.435 m/s | Mach (sea level, 15 °C) to metres per second |
| 2 Ma | 680.58 m/s | Mach (sea level, 15 °C) to metres per second |
| 2.5 Ma | 850.725 m/s | Mach (sea level, 15 °C) to metres per second |
| 3 Ma | 1,020.87 m/s | Mach (sea level, 15 °C) to metres per second |
| 5 Ma | 1,701.45 m/s | Mach (sea level, 15 °C) to metres per second |
| 10 Ma | 3,402.9 m/s | Mach (sea level, 15 °C) to metres per second |
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 m/s?
340.29 m/s at sea level and 15 °C.
Does it change with altitude?
Yes — the speed of sound tracks air temperature, so at cruise altitude Mach 1 is about 295 m/s.
What is Mach 2?
680.6 m/s at sea level.
Why does temperature matter and not pressure?
Because the speed of sound depends on the square root of absolute temperature, and pressure cancels out for an ideal gas.
What is a hypersonic speed?
Mach 5 and above — over 1,700 m/s at sea level.
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.