km/h to mph Converter

1. Type a speed in km/h.
2. Read the answer in mph, plus m/s, knots and pace per mile or km.
3. Tap mph to km/h to convert the other way. The real speed stays the same.

Kilometers per hour (km/h) is the speed unit on road signs and speedometers in most countries. Miles per hour (mph) is used in the United States and the United Kingdom.

A mile is longer than a kilometer, so the mph number is always smaller. 100 km/h is only about 62 mph.

Quick estimate: multiply km/h by 6, then drop the last digit. 90 km/h becomes 54, close to the exact 55.9 mph.

Limits vary by country and road. Always follow the posted signs.

Speedometer Error

Car speedometers often read a little high on purpose, so GPS speed can be lower.

Rounding

0.62 instead of 0.621371 is close enough for driving, not for lab work.

Average vs Top Speed

Convert the figure you actually need.

Driving Abroad

Read foreign road signs in the units your car shows.

Car and Bike Specs

Compare top speeds from different countries.

Running and Cycling

Turn treadmill km/h into mph pace.

1. Multiplying by 1.6

That turns mph into km/h. For km/h to mph, divide by 1.609.

2. Using Km/h for Knots

A knot is 1.852 km/h, used at sea and in the air.

3. Forgetting the Sign Units

Check whether a sign shows km/h or mph before you convert.

If your car shows mph but the signs show km/h, remember a few anchors: 50 km/h is about 30 mph, 80 km/h is about 50 mph, 100 km/h is about 62 mph and 120 km/h is about 75 mph.

Many rental cars in Europe and Canada show km/h in large numbers and mph in small ones, or the other way around. Check which ring the needle points to before you set your speed.

Multiply by 6 and drop the last digit. 70 km/h becomes 420, then 42 mph; the exact answer is 43.5 mph. Another quick way is to halve the km/h and add 10 percent of the original: 100 km/h becomes 50 + 10 = 60 mph, close to 62.

Both tricks land within about 3 percent, which is fine on the road but not for homework or specs.

Treadmills in metric countries show km/h. Use this table or the converter to match a training plan written in mph.

Only a few countries still post road speeds in mph: the United States, the United Kingdom and a handful of territories that follow their rules. Canada, Australia, Ireland and almost all of Europe, Asia, Africa and South America use km/h.

Planes and ships use knots in every country, while science and weather reports often use meters per second. When you see a speed with no unit, check the source country before converting.

A mile is exactly 1.609344 km, so the math is exact. Only the display is rounded.

Divide the km/h by 1.609, or multiply by 0.6214. For example, 80 km/h is 49.7 mph.

100 km/h is 62.14 mph.

120 km/h is 74.56 mph.

50 km/h is 31.07 mph.

No. 1 mph is faster than 1 km/h. One mph is 1.609 km/h.

Yes. Tap mph to km/h and type the speed. There is also a dedicated mph to km/h converter linked below.

200 km/h is 124.27 mph.

A mile is exactly 1,609.344 meters, which is 1.609344 km.

30 km/h is 18.64 mph, a common school-zone limit.

80 km/h is 49.71 mph, a common rural speed limit in many countries.

90 km/h is 55.92 mph.

Look at the small inner ring on the speedometer, or switch the digital display to km/h. As a guide, 100 km/h is about 62 mph and 50 km/h is about 31 mph.

• Unit conversion (US National Institute of Standards and Technology).
• NIST Handbook 44 (NIST; US customary unit definitions).
• NIST Guide to the SI, Appendix B: conversion factors (NIST Special Publication 811).