Speed Converter
Convert mph, km/h, m/s, knots, and feet per second.
Unit
Speed Converter
Generated on April 24, 2026
?What is the Speed Converter?
A speed converter handles the various ways we describe how fast something moves: kilometers per hour for driving in most countries, miles per hour for driving in the US and UK, meters per second for physics, knots for sailing and aviation, and feet per second for ballistics. Being able to move cleanly between these units is useful for drivers crossing borders, pilots reading charts, runners translating training paces, physicists doing homework, and sailors planning a route.
The Formula
Meters per second is the SI base, and all conversions route through it. Knots are a nautical convention: 1 knot = 1 nautical mile per hour = 1.852 km/h. The nautical mile itself is defined as 1 minute of arc along a meridian — roughly 1,852 meters — which makes navigation and chart work much easier because the latitude lines on a map correspond directly to travel distance. For land-based problems, the mph/kmh pair is more common.
Practical Examples
60 mph equals 96.56 km/h — the speed limit on most US interstate highways, converted to metric.
100 km/h equals 62.14 mph — the typical motorway speed in Europe and Pakistan, translated for US drivers.
10 m/s equals 36 km/h — useful for physics problems that pair SI units with everyday intuition.
1 knot equals 1.852 km/h (1.151 mph) — a cruise ship at 25 knots is doing about 46 km/h or 29 mph.
Usain Bolt's peak sprint speed was roughly 44.72 km/h or 27.78 mph — the fastest a human has ever officially run.
The speed of sound in air at room temperature is about 343 m/s, or 1,236 km/h — the basis for the Mach number used in aviation.