10 free speed conversion tools. Convert between mph, km/h, m/s, knots, and mach instantly.
Our speed converter tools provide 10 different ways to convert between five common speed units: miles per hour (mph), kilometres per hour (km/h), metres per second (m/s), knots, and Mach. Whether you're planning a road trip, calculating running pace, working in aviation, or studying physics, these tools give you instant, accurate conversions.
Speed conversion is essential in many fields. Miles per hour is the standard for road speeds in the UK and US, while kilometres per hour is used in most other countries. Metres per second is the SI unit commonly used in physics and engineering. Knots are used in maritime and aviation contexts, and Mach measures speed relative to the speed of sound. Understanding these different units helps in navigation, transportation, and scientific work.
All calculations process locally in your browser — no data is ever sent to our servers. Each tool focuses on a specific conversion pair, making it easy to get exactly what you need.
Miles per hour to kilometres per hour
Kilometres per hour to miles per hour
Miles per hour to metres per second
Metres per second to miles per hour
Kilometres per hour to metres per second
Metres per second to kilometres per hour
Miles per hour to knots
Knots to miles per hour
Kilometres per hour to knots
Knots to kilometres per hour