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Convert Calc

Miles per Hour (mph) to Kilometers per Hour (km/h) Converter

Enter a value to instantly convert between speed units.

Precision4 dp

1 Mile per Hour = 1.6093 Kilometer per Hour

Key Formulas

Kilometer per Hour → Mile per Hour

mph = km/h × 0.621371

Mile per Hour → Kilometer per Hour

km/h = mph × 1.60934

Knot → Mile per Hour

mph = kn × 1.15078

Mile per Hour → Knot

kn = mph × 0.868976

Formula

km/h = mph × 1.60934

One mile per hour equals 1.60934 kilometers per hour. Miles per hour are used in the US, UK, and a few others. Kilometers per hour are the global standard. Cross the border into Canada or Mexico in your US rental car, and suddenly your speedometer reads mph but the road signs are in km/h—that's when you need this conversion to avoid a speeding ticket.

Source: NIST SP 811, Table B.8

Frequently Asked Questions

Real-World Examples

US residential zone or school zone speed limit. Slow urban driving to protect pedestrians.

25 mph = 40.23 km/h

US rural road speed limit. Common on smaller roads outside cities; matches European 90 km/h zones.

55 mph = 88.51 km/h

US interstate highway speed limit. Standard on major highways; similar to European 120 km/h motorways.

70 mph = 112.65 km/h

High speed or very fast driving. Illegal on most public roads; used for racing or hypothetical scenarios.

100 mph = 160.93 km/h