Speed Converter
Global transit hub for automotive, maritime, and aerospace velocity standards. Precise conversion across metric, imperial, and nautical systems.
Conversion Factor
Multiply the speed value by 0.621371 to get the result in miles per hour.
Velocity vs Speed
While often used interchangeably in casual conversation, speed is a scalar quantity representing how fast an object is moving, while velocity is a vector quantity that includes direction.
In global transit, various standards are used: Knots for maritime and aviation navigation, Mach for supersonic flight, and km/h or mph for land-based transportation.
Common Conversion Formulas
Common Speed Reference
Mach (Ma)
The ratio of an object's speed to the speed of sound. Mach 1 ≈ 1,234.8 km/h.
Knot (kn)
One nautical mile per hour. Used globally for meteorology and maritime and aviation navigation.
km/h
The standard unit for road traffic in most of the world. 1 km/h ≈ 0.278 m/s.
Feet per second
Common in ballistics and aeronautics in the United States and UK.
Metric to Imperial Speed Reference
| Metric Limit | Imperial Equivalent | Transit Context |
|---|---|---|
| 30 km/h | 18.6 mph | School zones and residential areas |
| 50 km/h | 31.1 mph | Standard urban speed limit |
| 80 km/h | 49.7 mph | Rural roads and minor highways |
| 100 km/h | 62.1 mph | Major highways and expressways |
| 120 km/h | 74.6 mph | Motorway/Freeway limits in Europe |
Specialized Applications
Aviation Hub
Convert Ground Speed (GS) and Indicated Airspeed (IAS) between knots and Mach for flight planning and ATC communication.
Maritime Logistics
Navigate global waters by converting vessel speed in knots to standard metric or imperial units for estimated arrival times.
Sports Performance
Analyze athletic sprints, ball velocity, or cycling pace across multiple scientific measurement standards.