How to convert miles per hour to kilometers per hour
To convert miles per hour to kilometers per hour, multiply each value by the exact factor in the box: 1 mile per hour = 1.609344 kilometers per hour exactly. There is no rounding anywhere in the chain — the display trims the final answer to six decimal places, and converting the result back with the inverse page returns your starting number.
Miles per hour is the road speed of the United States and the United Kingdom; kilometers per hour is the road speed of almost everywhere else, and of every weather report and cycling computer on earth. Because the mile is exactly 1.609344 km, mph converts to km/h with the same exact factor as the distance itself — the “per hour” is common to both sides and changes nothing. This page's table is the speed-limit range, 5 to 100 mph, because limits and cruise speeds are what get converted.
The anchors are worth memorising: a 20 mph school zone is 32.19 km/h, a 30 mph town limit is 48.28 km/h, this page's 60 mph default is 96.56 km/h, and the 70 mph motorway and interstate standard is 112.65 km/h. Wind speeds cross systems in every storm report — a 75 mph hurricane threshold is 120.7 km/h, a 100 mph gust is 160.93 km/h — and imported vehicles with mph speedometers meeting km/h limits are the everyday case for the conversion's other direction of travel.
The common mistake is the ×1.6 shortcut presented as the answer rather than an estimate: at 70 mph it reads 112 against the true 112.65 km/h, harmless — but at 30 mph in a foreign school zone the same habit, reversed, is how visitors misjudge limits. The subtler trap is averaging: converting a journey's average speed works with the same factor, but converting a speedometer reading mid-trip and mentally rounding to the nearest sign (“96 is basically 100”) quietly legalises 4 km/h of overspeed. Keep the exact figure until you compare it with the limit.
Worked example
60 miles per hour is 96.56064 kilometers per hour: 60 × 1.609344 = 96.56064 — highway cruising speed on both sides of the Atlantic, a notch under the metric world's 100.
How to use this converter
- Enter your value in miles per hour in the box above — the result updates as you type.
- Read the converted value in kilometers per hour in the headline panel.
- Check the factor, the formula and the inverse result (your answer converted back) in the stats if you need to show your working.
- Use the Miles per hour to Kilometers per hour conversion table below for other common values without typing each one.