Free Engineering Tool
Speed & Velocity Converter
Convert between all common speed and velocity units instantly. Enter a value in any unit and see all conversions simultaneously.
All Conversions
Speed Unit Definitions
Speed is a scalar quantity measuring how fast an object moves. Velocity includes direction (vector). For unit conversion purposes, only the magnitude matters.
| Unit | Symbol | Equals (m/s) | Notes |
|---|---|---|---|
| Meter per second | m/s | 1.0000 | SI base unit |
| Kilometer per hour | km/h | 0.27778 | 1 km/h = 1000/3600 m/s |
| Mile per hour | mph | 0.44704 | 1 mile = 1609.344 m |
| Foot per second | ft/s | 0.30480 | 1 ft = 0.3048 m exactly |
| Foot per minute | ft/min | 0.00508 | Common for surface speed |
| Knot | kn | 0.51444 | 1 nautical mile/hour |
| Mach (20 °C) | Ma | 343.21 | Speed of sound in air at 20 °C |
Mach Number
The Mach number is the ratio of flow velocity to the local speed of sound. At 20 °C in dry air, the speed of sound is approximately 343.21 m/s (1235.6 km/h).
At sea level standard conditions (15 °C), a ≈ 340.3 m/s. This calculator uses 20 °C (a = 343.21 m/s).
Common Reference Speeds
| Reference | m/s | km/h | mph |
|---|---|---|---|
| Walking speed | 1.4 | 5.0 | 3.1 |
| City driving | 13.9 | 50 | 31.1 |
| Highway driving | 33.3 | 120 | 74.6 |
| Speed of sound (20 °C) | 343.2 | 1235.6 | 767.7 |
| Bullet (rifle) | ~900 | ~3240 | ~2013 |
Tip: For rotating machinery, surface speed (m/s or ft/min) = π × D × n / 60, where D is diameter in meters and n is RPM.
Professional field balancing instruments and software. Used in 50+ countries.
Nikolai Shelkovenko
Nikolai Shelkovenko is a vibration analysis engineer and the founder and CEO of Vibromera. For more than 15 years he has balanced rotating equipment in the field rather than on a test bench: mulchers, industrial fans, crushers, centrifuges, shafts and spindles. That work is what the Balanset instruments grew out of — they were designed as a tool a specialist can carry to the machine and use alone, on site, not as laboratory equipment. Vibromera was founded in 2017 and has been based in Porto, Portugal, since 2023. Development, assembly and support of the Balanset line all happen here. The flagship instrument is the Balanset-1A, a portable analyser for single- and two-plane balancing and for vibration diagnostics. Nikolai is personally involved in customer support, in working through difficult balancing cases and in the development of the software. He works with customers worldwide, in any language.
