Kilometers ⇄ Miles Converter

How to convert kilometers to miles

To convert kilometers to miles, divide the value by 1.609344, or multiply it by about 0.621371.

mi = km ÷ 1.609344

Example: 10 km ÷ 1.609344 = 6.21371 mi

How to convert miles to kilometers

To convert miles to kilometers, multiply the value by 1.609344.

km = mi × 1.609344

Example: 10 mi × 1.609344 = 16.0934 km

1 km = 0.621371 mi · 1 mi = 1.60934 km

A mile is exactly 1.609344 kilometers, or 5,280 feet. Road distances and speed limits are given in miles in the United States and the United Kingdom, and in kilometers almost everywhere else. A marathon is 42.195 km, about 26.2 miles.

Kilometers, miles and their history

A kilometer is simply 1,000 meters. The mile goes back to the Roman mille passuum, “a thousand paces”, and the English statute mile was fixed at 8 furlongs, or 5,280 feet, by an Act of Parliament in 1593. Canada, Australia and Ireland all switched their road signs from miles to kilometers in the second half of the 20th century or later, which is why older maps and guidebooks from those countries can still show miles.

Beyond roads, miles live on in sport: athletics still runs the mile race, and many runners in the US and UK log their training in miles even when the race itself is measured in kilometers.

Running distances and pace

Road races are named in kilometers almost everywhere, including in the United States. A 5K is 3.11 miles, a 10K is 6.21 miles and a half marathon is 13.1 miles. The 1,500 m on the track, often called the “metric mile”, is 0.93 miles, about 109 m short of a real mile.

Running apps and watches show pace either per kilometer or per mile. Because a mile is longer, your time per mile is 1.609 times your time per kilometer:

Going the other way, a 10-minute mile is a pace of 6:13 per kilometer, and an 8-minute mile is 4:58 per kilometer.

Quick mental math

• The Fibonacci trick. Neighboring numbers in the Fibonacci sequence (3, 5, 8, 13, 21, 34, 55…) are almost exact mile–kilometer pairs: 5 mi ≈ 8 km, 8 mi ≈ 13 km, 13 mi ≈ 21 km and 34 mi ≈ 55 km. It works because the ratio between neighbors approaches 1.618, very close to the 1.609 kilometers in a mile.
• Five-eighths. For kilometers to miles, divide by 8 and multiply by 5: 80 km → 10 × 5 = 50 mi (exact: 49.71 mi), less than 1% high. Reverse it for miles to kilometers: 50 mi ÷ 5 × 8 = 80 km (exact: 80.47 km).

Common mistakes

• Confusing statute and nautical miles. Ships and aircraft use the nautical mile of exactly 1,852 m, about 15% longer than an ordinary mile. A distance in “miles” on a sea chart or a flight plan is nautical.
• Converting pace like a distance. A pace is time per distance, so you multiply minutes per kilometer by 1.609 to get minutes per mile. Dividing gives an impossibly fast pace.
• Rounding on long trips. Using 1.6 is fine for a short drive, but on a 500-mile road trip it puts you almost 5 km short.

FAQ

How long does it take to walk a kilometer or a mile?

At a typical walking speed of about 5 km/h (3.1 mph), a kilometer takes about 12 minutes and a mile about 19 minutes.

Is a 10K more or less than 6 miles?

A little more: 10 km is 6.21 miles. A 15K is 9.32 miles, just short of ten.

How many kilometers is 100 miles?

160.93 km. In ultra running, a “100-miler” is therefore much longer than a 100 km race, which is only 62.14 miles.

Do speeds convert with the same numbers?

Yes. Kilometers per hour and miles per hour use the same factor, so 100 km/h is 62.1 mph. See km/h to mph for speed limits and more.

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