mph to km/h Converter

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Convert miles per hour to kilometers per hour at the exact factor 1 mph = 1.609344 km/h. Anchors: 30 mph = 48.28 km/h (US residential), 60 mph = 96.56 km/h, 75 mph = 120.70 km/h (US Interstate), 100 mph = 160.93 km/h. Useful when reading US speed limits, NASCAR data or sport-car top speeds and reporting them in metric units. Browser-local.

Mile per hour (mph)
Kilometer per hour (km/h)

Mile per hour (mph) → Kilometer per hour (km/h)

Quick reference table

Mile per hour (mph)Kilometer per hour (km/h)
10 mph16.0934 km/h
25 mph40.2336 km/h
50 mph80.4672 km/h
60 mph96.5606 km/h
80 mph128.7475 km/h
100 mph160.9344 km/h
120 mph193.1213 km/h
150 mph241.4016 km/h
200 mph321.8688 km/h

Glossary

Mile per hour (mph)

A mile per hour is the customary speed unit used in the United States, the United Kingdom and a few other countries for road traffic, athletic events and weather reports. 1 mph = 1.6093 km/h = 0.4470 m/s. Typical US highway limits are 55–75 mph; a 100 m sprinter peaks at about 27 mph; a hurricane is sustained winds above 74 mph.

Kilometer per hour (km/h)

A kilometer per hour is the everyday speed unit used on road signs, vehicle speedometers and weather forecasts in nearly every country except the United States and the United Kingdom. 1 km/h = 0.2778 m/s = 0.6214 mph. Highway speed limits are commonly 100–130 km/h; a marathon world record pace is about 21 km/h.

Metric / SI speed

In the metric system, speed is reported in meters per second (scientific) or kilometers per hour (everyday). The relation is exact: 1 m/s = 3.6 km/h. Most countries use km/h on road signs and speedometers; m/s appears in physics, engineering, weather data and athletics where fine-resolution timing matters.

Imperial / US Customary speed

In the United States, the United Kingdom and a few other countries, road speeds are reported in miles per hour (mph). US engineering also uses feet per second (ft/s). 1 mph = 1.6093 km/h = 0.4470 m/s. Maritime and aviation worldwide use knots (1 knot = 1.852 km/h), independent of the metric/imperial divide.

Related tools

km/h to mph
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mph to m/s
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Speed Converter
Convert speed — m/s, km/h, mph, knots, ft/s, mach