Speed Converter
Convert between km/h, mph, m/s, knots, Mach, and other speed units instantly
Quick Examples
What is Speed Conversion?
Speed conversion is the process of converting velocity measurements from one unit to another. Different countries and industries use various speed units, making conversion essential for international communication, travel, and scientific work.
Our speed converter supports the most commonly used units including kilometers per hour (km/h), miles per hour (mph), meters per second (m/s), feet per second (ft/s), knots, and even Mach numbers. All conversions are performed instantly with high precision using standard conversion factors.
Common Speed Units Explained
Kilometers per Hour (km/h)
The standard unit used in most countries worldwide for road speed limits and vehicle speedometers. One km/h equals 0.278 meters per second.
Miles per Hour (mph)
Primarily used in the United States, United Kingdom, and a few other countries. One mph equals approximately 1.609 km/h or 0.447 m/s.
Meters per Second (m/s)
The SI (International System of Units) standard for velocity. Commonly used in scientific calculations and physics. It's the base unit for our converter.
Knots
Used primarily in maritime and aviation contexts. One knot equals one nautical mile per hour, or approximately 1.852 km/h.
Mach Number
Represents speed relative to the speed of sound in air. Mach 1 is approximately 343 m/s at sea level and 20°C. Used for high-speed aircraft.
When Do You Need Speed Conversion?
International Travel
When driving or renting vehicles in foreign countries, understanding speed limits in different units is crucial for safety and legal compliance.
Sports & Athletics
Track and field events, cycling, swimming, and other sports often require speed conversions for international competitions and record keeping.
Aviation & Maritime
Pilots and sailors regularly convert between knots, kilometers per hour, and other units for navigation, flight planning, and communication.
Scientific Research
Physics experiments, engineering calculations, and academic research often require precise speed conversions between SI and imperial units.
Frequently Asked Questions
How accurate is this speed converter?
Our converter uses standard conversion factors recognized internationally and provides results accurate to 6 decimal places. This level of precision is suitable for most practical applications.
What's the difference between mph and km/h?
Miles per hour (mph) uses the imperial system while kilometers per hour (km/h) uses the metric system. One mile equals approximately 1.609 kilometers, so 60 mph is roughly 97 km/h.
Does the Mach number change with altitude?
Yes, the speed of sound varies with temperature and air pressure. Our converter uses the standard value at sea level (343 m/s). At higher altitudes where it's colder, the speed of sound is lower.
Is my data safe when using this tool?
Absolutely! All conversions happen entirely in your browser using JavaScript. No data is transmitted to any server, ensuring complete privacy and security.
Can I use this for professional or commercial purposes?
Yes! This tool is completely free to use for any purpose, including commercial applications. However, for critical safety or engineering applications, always verify results with official references.