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.
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 |
|---|---|---|
| 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 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.