Speed Converter
The speed converter allows you to quickly and accurately convert between the most common units of speed and velocity. Whether you're working with kilometers per hour, miles per hour, meters per second, or knots, this tool handles the math instantly.
Speed conversions are essential in transportation, aviation, maritime navigation, physics, and sports. With different countries and industries using different speed units, the ability to convert between them is a practical everyday skill.
How it works
Speed conversions use standardized factors. All units are converted through a base unit (meters per second). For example: 1 km/h = 0.2778 m/s, 1 mph = 0.44704 m/s, 1 knot = 0.514444 m/s. To convert between any two units, the value is first converted to m/s, then to the target unit.
Use cases
- Converting vehicle speeds between km/h and mph for international travel
- Converting wind speeds between knots and km/h for weather and aviation
- Converting running or cycling speeds between different units for sports tracking
- Physics calculations involving velocity in different unit systems
Frequently asked questions
How do I convert km/h to mph?
Multiply the km/h value by 0.621371, or divide it by 1.60934. For example, 100 km/h equals about 62.1 mph. The converter does this instantly by routing the value through meters per second, where 1 km/h = 0.2778 m/s.
How many mph is 100 km/h?
100 km/h is approximately 62.14 mph. Highway speed limits of 100 or 120 km/h in metric countries correspond to roughly 62 mph and 75 mph, which is useful to know when driving abroad.
What is a knot in km/h?
One knot equals exactly 1.852 km/h, because a knot is one nautical mile per hour and a nautical mile is 1,852 meters. Knots are the standard speed unit in maritime navigation and aviation. In m/s, one knot equals about 0.514444 m/s.
How do I convert m/s to km/h?
Multiply the meters-per-second value by 3.6 to get km/h, since there are 3,600 seconds in an hour and 1,000 meters in a kilometer. For example, 10 m/s equals 36 km/h. To go the other way, divide km/h by 3.6.
What is the difference between speed and velocity?
Speed is a scalar quantity that measures only how fast something moves, while velocity is a vector that also includes direction. The units are identical (km/h, m/s, mph), so this converter works for both magnitudes. In everyday use the two terms are often treated as interchangeable.