What is mach (approx at sea level)?
Mach is a dimensionless speed unit expressing the ratio of an object’s speed to the local speed of sound. At sea level, Mach 1 is approximately 343 m/s. It is used in aviation and aerodynamics to characterise high-speed flight regimes.
Real-world uses
Mach numbers are used in aerospace engineering and aviation to describe aircraft speed relative to the speed of sound. Commercial jets cruise near Mach 0.85, military fighters reach Mach 2+, and hypersonic vehicles exceed Mach 5.
History
Named after Austrian physicist Ernst Mach, who studied supersonic projectiles in the 1880s. The Mach number was formally defined by Swiss engineer Jakob Ackeret in 1929. Chuck Yeager first broke the sound barrier (Mach 1) in 1947 in the Bell X-1.
Common mistakes
Treating Mach as a fixed speed—it varies with altitude and temperature because the speed of sound changes. Mach 1 is about 343 m/s at sea level (15°C) but about 295 m/s at 11,000 m altitude.
What is metre per second?
Metre per second is the SI unit of speed. It is used in physics, engineering, and scientific contexts to express velocity, and serves as the reference unit for all speed calculations in this converter.
Real-world uses
Metres per second is the SI unit of speed used in physics, engineering, and scientific research. Wind speed in meteorological data, projectile velocities, and fluid flow rates are expressed in m/s. The speed of sound at sea level is approximately 343 m/s.
History
As an SI derived unit, metres per second became the standard scientific speed unit with the adoption of the SI system in 1960. It naturally combines the base units of length (metre) and time (second).
Common mistakes
Forgetting to convert from km/h—divide by 3.6, not by 3.0 or 60. Also, confusing velocity (vector with direction) with speed (scalar magnitude), both expressed in m/s but with different physical meanings.
When is this conversion used?
Converting mach (approx at sea level) to metre per second is useful in the speed domain when comparing values across different measurement standards or applying formulas that require a specific unit.
Worked examples
1 mach (approx at sea level) = 340.29 metre per second
1 metre per second = 1 metre per second
How to convert mach (approx at sea level) to metre per second
To convert mach (approx at sea level) to metre per second, multiply the value by 340.29.
To convert metre per second back to mach (approx at sea level), multiply by 0.00293867.
Measurement standards
The SI unit of speed is metres per second (m/s), a derived unit requiring no independent definition. The knot is defined as exactly one nautical mile (1,852 metres) per hour and is sanctioned for maritime and aeronautical navigation by the International Civil Aviation Organization.
Did you know?
The fastest human-made object is the Parker Solar Probe, which reached 635,266 km/h (about 176 km/s) in 2024 during a close pass of the Sun — fast enough to travel from New York to Tokyo in under a minute.
Quick reference: mach (approx at sea level) to metre per second
| mach (approx at sea level) | metre per second |
|---|---|
| 0.1 | 34.029 |
| 0.5 | 170.145 |
| 1 | 340.29 |
| 2 | 680.58 |
| 5 | 1,701.45 |
| 10 | 3,402.9 |
| 25 | 8,507.25 |
| 50 | 17,014.5 |
| 100 | 34,029 |
| 250 | 85,072.5 |
| 500 | 170,145 |
| 1,000 | 340,290 |
Common values
| mach (approx at sea level) | metre per second | |
|---|---|---|
| Walking speed | 0.00411414 mach (approx at sea level) | 1.4 metre per second |
| City speed limit | 0.04084751 mach (approx at sea level) | 13.9 metre per second |
| Highway driving | 0.09198037 mach (approx at sea level) | 31.3 metre per second |
| Commercial aircraft | 0.73466749 mach (approx at sea level) | 250 metre per second |
| Speed of sound (sea level) | 1 mach (approx at sea level) | 340.29 metre per second |
Available Speed units
More mach (approx at sea level) conversions
- Convert mach (approx at sea level) to metre per second
- Convert mach (approx at sea level) to kilometre per hour
- Convert mach (approx at sea level) to mile per hour
- Convert mach (approx at sea level) to knot
- Convert mach (approx at sea level) to foot per second
- Convert mach (approx at sea level) to metre per minute
- Convert mach (approx at sea level) to kilometre per second
- Convert mach (approx at sea level) to centimetre per second
- Convert mach (approx at sea level) to mile per minute
Assumption: Mach uses an approximate sea-level reference (about 340.29 m/s).