Speed Converter
Use this speed converter to easily convert between different speed units including mph, km/h, m/s, knots, and more.
Popular Speed Conversions
Complete List of Speed Units for Conversion
1 kilometer/hour [km/h] = 0.277778 meter/second [m/s]
kilometer/hour to meter/second, meter/second to kilometer/hour
1 mile/hour [mph] = 0.447040 meter/second [m/s]
1 meter/hour [m/h] = 0.000277778 meter/second [m/s]
1 meter/minute [m/min] = 0.0166667 meter/second [m/s]
1 kilometer/minute [km/min] = 16.6667 meter/second [m/s]
kilometer/minute to meter/second, meter/second to kilometer/minute
1 kilometer/second [km/s] = 1000.00 meter/second [m/s]
kilometer/second to meter/second, meter/second to kilometer/second
1 centimeter/hour [cm/h] = 0.00000277778 meter/second [m/s]
centimeter/hour to meter/second, meter/second to centimeter/hour
1 centimeter/minute [cm/min] = 0.000166667 meter/second [m/s]
centimeter/minute to meter/second, meter/second to centimeter/minute
1 centimeter/second [cm/s] = 0.0100000 meter/second [m/s]
centimeter/second to meter/second, meter/second to centimeter/second
1 millimeter/hour [mm/h] = 2.77778e-7 meter/second [m/s]
millimeter/hour to meter/second, meter/second to millimeter/hour
1 millimeter/minute [mm/min] = 0.0000166667 meter/second [m/s]
millimeter/minute to meter/second, meter/second to millimeter/minute
1 millimeter/second [mm/s] = 0.00100000 meter/second [m/s]
millimeter/second to meter/second, meter/second to millimeter/second
1 foot/hour [ft/h] = 0.0000846667 meter/second [m/s]
1 foot/minute [ft/min] = 0.00508000 meter/second [m/s]
1 foot/second [ft/s] = 0.304800 meter/second [m/s]
1 yard/hour [yd/h] = 0.000254000 meter/second [m/s]
1 yard/minute [yd/min] = 0.0152400 meter/second [m/s]
1 yard/second [yd/s] = 0.914400 meter/second [m/s]
1 mile/minute [mi/min] = 26.8224 meter/second [m/s]
1 mile/second [mi/s] = 1609.34 meter/second [m/s]
1 knot [kn] = 0.514444 meter/second [m/s]
1 knot (UK) [kn (UK)] = 0.514773 meter/second [m/s]
1 speed of light [c] = 2.99792e+8 meter/second [m/s]
speed of light to meter/second, meter/second to speed of light
1 cosmic velocity - first [v₁] = 7900.00 meter/second [m/s]
cosmic velocity - first to meter/second, meter/second to cosmic velocity - first
1 cosmic velocity - second [v₂] = 11200.0 meter/second [m/s]
cosmic velocity - second to meter/second, meter/second to cosmic velocity - second
1 cosmic velocity - third [v₃] = 16700.0 meter/second [m/s]
cosmic velocity - third to meter/second, meter/second to cosmic velocity - third
1 Earth's velocity [v⊕] = 29800.0 meter/second [m/s]
Earth's velocity to meter/second, meter/second to Earth's velocity
1 speed of sound in pure water [vs (H₂O)] = 1482.00 meter/second [m/s]
speed of sound in pure water to meter/second, meter/second to speed of sound in pure water
1 speed of sound in sea water [vs (sea)] = 1522.00 meter/second [m/s]
speed of sound in sea water to meter/second, meter/second to speed of sound in sea water
1 Mach (20°C, 1 atm) [Mach] = 343.000 meter/second [m/s]
Mach (20°C, 1 atm) to meter/second, meter/second to Mach (20°C, 1 atm)
1 Mach (SI standard) [Ma] = 295.046 meter/second [m/s]
Mach (SI standard) to meter/second, meter/second to Mach (SI standard)
How this speed converter works
The base speed unit is the meter per second (m/s), which is the SI derived unit for speed. All other units are defined as fixed multiples or fractions of m/s, based on SI definitions and internationally accepted constants.
Common speed unit relationships
- 1 m/s = 3.6 km/h
- 1 mph ≈ 0.44704 m/s
- 1 knot = 1.852 km/h
- 1 ft/s ≈ 0.3048 m/s
When to use each speed unit
Kilometers per hour (km/h) are the standard speed unit in most countries for road travel and everyday use. Miles per hour (mph) are predominantly used in the United States, United Kingdom, and a few other countries. Meters per second (m/s) is the SI unit used in physics, engineering, and scientific calculations. Knots are the standard speed unit in aviation and maritime navigation, defined as one nautical mile per hour. Feet per second (ft/s) is sometimes used in engineering applications in countries using imperial units.
Speed conversion accuracy
Our speed converter uses exact conversion factors defined by international standards organizations. The conversions are based on the International System of Units (SI) and provide precision suitable for engineering, scientific, and educational applications.
Frequently Asked Questions
- Which speed units are supported?
- We support meters per second, kilometers per hour, miles per hour, feet per second, knots, Mach numbers, and several astronomical and reference velocities including the speed of light and Earth's orbital velocity.
- How accurate are the speed conversions?
- Speed conversions use fixed relationships based on SI definitions and conventional constants, providing high precision suitable for engineering, scientific, and educational purposes.
- What is the difference between knots and mph?
- A knot is one nautical mile per hour, which equals approximately 1.15078 mph. Knots are primarily used in maritime and aviation contexts, while mph is used for land-based speed measurements.