Speed Converter - km/h, mph, m/s, knots | Hexa

Understanding Speed Units Across the World

Speed is measured differently by region and context. Americans use miles per hour (mph). Most of the world uses kilometers per hour (km/h). Scientists and engineers often use meters per second (m/s). Aviation and maritime use knots (nautical miles per hour). A car speedometer might show 120 km/h—that's about 75 mph. A plane cruising at 500 knots is roughly 926 km/h. Converting between these units is essential for travel, sports, engineering, and understanding international data. Our converter handles km/h, mph, m/s, knots, and more. Enter any value, get instant conversion. See Conversion of units on Wikipedia for the full picture.

Common Speed Units Explained

km/h (kilometers per hour): The metric standard. Used in most countries for road speed limits, vehicle specs, and weather (wind speed). 100 km/h ≈ 62 mph.

mph (miles per hour): Used in the US, UK, and a few other countries. Road signs, car dashboards, and weather reports. 60 mph ≈ 97 km/h.

m/s (meters per second): Common in physics and engineering. Wind speed, terminal velocity, and scientific calculations. 10 m/s ≈ 36 km/h ≈ 22 mph.

Knots: Nautical miles per hour. Used in aviation and maritime. 1 knot ≈ 1.852 km/h ≈ 1.151 mph. A "knot" originally referred to the knots on a rope used to measure ship speed.

When Speed Conversion Matters

Driving abroad: Renting a car in Europe? Speed limits are in km/h. Convert your familiar mph to km/h so you know what 50, 90, or 130 means.

Sports and fitness: Running pace (min/km vs min/mile), cycling speed, swimming speed—different sports use different units. Convert to compare or set goals.

Weather: Wind speed in km/h, mph, or m/s. Hurricane categories use mph; many weather apps use km/h. Convert to understand the forecast.

Aviation and maritime: Flight plans and nautical charts use knots. Convert to km/h or mph for land-based reference.

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Open the speed converter below. Enter a value in km/h, mph, m/s, or knots. Get the equivalent in other units. No signup required.