KM/H to MPH Converter - Free Online Tool

Convert kilometers per hour to miles per hour instantly. 1 km/h = 0.621371 mph. Fast speed conversion. No signup, works offline.

Quick Reference

km/h	mph	Context
30 km/h	18.6 mph	Residential street
50 km/h	31.1 mph	City driving
80 km/h	49.7 mph	Rural road
100 km/h	62.1 mph	Highway speed
120 km/h	74.6 mph	European motorway
130 km/h	80.8 mph	German Autobahn advisory

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Frequently Asked Questions

The formula is: mph = km/h × 0.621371. Alternatively: mph = km/h ÷ 1.60934. Both give identical results, derived from the fact that 1 kilometer equals 0.621371 miles.

Common situations include: understanding foreign vehicle specifications, converting GPS data for US maps, interpreting speed limits while planning US trips, comparing athletic performance (running/cycling speeds), and understanding weather reports (wind speeds in different countries).

The US retained the British imperial system after independence. When most countries adopted the metric system in the 19th-20th centuries for standardization, the US kept its traditional units. Only the US, Myanmar, and Liberia haven't officially adopted the metric system, though the UK uses mph for road speeds.

Quick method: divide km/h by 1.6. Even simpler: divide by 2, then add 25%. Example: 100 km/h ÷ 2 = 50, plus 12.5 = 62.5 mph (actual: 62.14). Or remember that 100 km/h ≈ 62 mph as a reference point.

Useful conversions: 50 km/h = 31 mph (urban), 80 km/h = 50 mph (suburban), 100 km/h = 62 mph (highway), 120 km/h = 75 mph (freeway), 130 km/h = 81 mph (European motorway limit). These help Americans understand international speed limits.

For everyday driving, rounding to the nearest mph is perfectly adequate. This converter provides decimal precision useful for GPS data, vehicle engineering specs, sports analytics, or scientific calculations where exactness matters.

Modern rental cars typically show both km/h and km/h on the speedometer dial. In metric countries, km/h numbers are larger and more prominent. Many digital displays allow switching between units. After a short adjustment period, most drivers adapt easily.

No. All conversions happen entirely in your browser using JavaScript. No data is transmitted to servers or stored anywhere. The tool works offline after initial page load, ensuring complete privacy.

This converter handles one value at a time for simplicity and accuracy. Enter your speed, view the instant result, copy if needed, then enter your next value. The immediate calculation makes batch conversions quick.

Remember '5 to 8': 5 mph ≈ 8 km/h (the exact ratio is 1.609). So 50 mph ≈ 80 km/h. Or use 60/100: 100 km/h = 60 mph (actually 62.1, but close). For precision, divide km/h by 1.6.

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