Metres per Second to Mach Converter
Convert metres per second to Mach number at sea level and 15 °C. Results update as you type; exact factors shown.
One metre per second is 0.0029 Mach (sea level, 15 °C) — see the exact factor, not a rounded rule of thumb.
How the metres per second to mach 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 |
|---|---|---|
| 50 m/s | 0.1469 Ma | metres per second to Mach (sea level, 15 °C) |
| 100 m/s | 0.2939 Ma | metres per second to Mach (sea level, 15 °C) |
| 200 m/s | 0.5877 Ma | metres per second to Mach (sea level, 15 °C) |
| 250 m/s | 0.7347 Ma | metres per second to Mach (sea level, 15 °C) |
| 300 m/s | 0.8816 Ma | metres per second to Mach (sea level, 15 °C) |
| 340.29 m/s | 1 Ma | metres per second to Mach (sea level, 15 °C) |
| 400 m/s | 1.1755 Ma | metres per second to Mach (sea level, 15 °C) |
| 500 m/s | 1.4693 Ma | metres per second to Mach (sea level, 15 °C) |
| 680 m/s | 1.9983 Ma | metres per second to Mach (sea level, 15 °C) |
| 1,000 m/s | 2.9387 Ma | metres per second to Mach (sea level, 15 °C) |
| 1,500 m/s | 4.408 Ma | metres per second to Mach (sea level, 15 °C) |
| 3,000 m/s | 8.816 Ma | metres per second to Mach (sea level, 15 °C) |
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 speed is Mach 1?
340.29 m/s at sea level, 15 °C.
What is 250 m/s in Mach?
About Mach 0.73.
Why the temperature qualifier?
Because Mach is a ratio to the local speed of sound, which falls with temperature. The same true airspeed is a higher Mach number at altitude.
What is an airliner cruise speed?
About 250 m/s true airspeed, which is Mach 0.85 at altitude but only Mach 0.73 at sea level.
Is Mach a unit?
No — it is a dimensionless ratio, which is why it needs a stated reference condition.
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.