KM To Miles Converter

1. Keep the direction on Kilometers to miles, or switch it to miles to kilometers.
2. Type the distance. Race distances such as 21.0975 or 42.195 are recognised and named.
3. Add a finish time in minutes if you want your pace per kilometer and per mile. Leave it blank for a plain conversion.

Here is what each result means:

A kilometer to mile conversion restates a metric distance in the international mile used in the United States and the UK. The kilometer is 1,000 meters, an SI unit. The mile is 1,760 yards, or 5,280 feet.

Since 1959 the yard has been fixed at 0.9144 m, which makes the mile exactly 1,609.344 m. NIST SP 811 lists the mile at 1.609344 km, and the UK Weights and Measures Act 1985 defines the mile as 1,760 yards. So the kilometer is about 62 percent of a mile.

Runners, drivers, cyclists and hikers need this most. The page does not cover the nautical mile of 1,852 m, which is 1.15078 statute miles and belongs to sea and air navigation.

You divide kilometers by 1.609344, because one mile holds exactly 1.609344 kilometers.

1. Start from the definition: 1 mi = 1,609.344 m = 1.609344 km.
2. Flip it: 1 km = 1 / 1.609344 = 0.621371192 mi. This decimal repeats forever, so every printed value is rounded.
3. Multiply your kilometers by that factor. For 10 km: 10 x 0.621371192 = 6.21371 mi.

Dividing by 1.609344 avoids the rounding in 0.621371, so the tool divides. The difference only shows past the sixth decimal.

The World Athletics Technical Rules list the standard road race distances, including the road mile of 1,609.344 m and the marathon of 42.195 km. The half marathon is half of that, 21.0975 km.

Worked example. A runner finishes a 10K in 55 minutes. 10 / 1.609344 = 6.21371 mi. Pace is 55 / 10 = 5:30 per km, and 55 / 6.21371 = 8:51 per mile. The pace calculator goes further, with split times and goal paces.

A speed in km/h converts to mph with the same factor, because the hour cancels out. 100 km/h is 62.14 mph.

Limits vary by country and road, so treat the third column as typical, not legal advice. The UK is a well-known exception: its limits are set in miles per hour, as in Schedule 6 of the Road Traffic Regulation Act 1984. For US drivers reading metric signs, mph to km/h explained covers the reverse.

Each value is kilometers / 1.609344, rounded to 4 decimals.

The mile is fixed, so differences come from which mile you mean, how the course was measured and how you round.

GPS Reads Longer than the Course

Race courses are measured along the shortest route a runner could take. World Athletics also requires a course to be no shorter than its official distance. Runners weave, so a watch often shows 42.5 km or more for a marathon.

The Retired US Survey Mile

Old US land surveys used a survey foot of 1200/3937 m. That survey mile is 1,609.347 m, about 3.2 mm longer. NIST retired the survey foot on January 1, 2023.

Rounding the Factor

Using 0.62 reads a marathon as 26.16 mi; the true value is 26.22 mi. Keep full precision until the final answer.

Statute vs Nautical Miles

A nautical mile is 1,852 m. Confusing the two puts a distance off by 15 percent.

For a quick estimate, multiply kilometers by 5/8. The error is small and always in the same direction.

Neighbouring Fibonacci numbers sit close to the ratio. 8 km is about 5 mi, 13 km about 8 mi, and 21 km about 13 mi. Each pair is off by under 1 percent: 8 km is really 4.971 mi.

Race Training

Plans written in miles meet races named in kilometers. The pace field turns a goal time into minutes per mile and per km in one step.

Driving Abroad

Rental cars in metric countries show km/h, and road signs show kilometers to the next town. Read the km/h value as mph with the speed result.

Cycling and Hiking

Trail maps and bike computers often use kilometers. A 30 km loop is 18.64 mi. For shorter metric spans, the meters to yards converter is a better fit.

Mixed Unit Lists

Imports, maps and fitness logs mix systems. The metric to imperial converter handles weight, volume and temperature in one place.

1. Multiplying When You Should Divide

10 km x 1.609344 gives 16.09, which is 10 miles in kilometers. Kilometers to miles makes the number smaller.

2. Calling the Marathon 26 Miles

The marathon is 26.2188 mi. That extra 0.22 mi, about 352 m, matters for pacing the finish.

3. Rounding the Half Marathon to 21 Km

21 km is 13.05 mi, but the half marathon is 21.0975 km, or 13.11 mi.

4. Using the Nautical Mile

Boat and aircraft speeds use knots, which are nautical miles per hour. They are not road miles.

5. Trusting a Phone for a Record

A GPS track is not a certified course measurement. Use the official race distance for pace and records.

The conversion is exact to the limit of the digits shown, because the mile is defined in meters.

A 5K is 3.10686 miles, usually written as 3.1 mi. It is 5,000 meters divided by 1,609.344 meters per mile.

A 10K is 6.21371 miles, or about 6.2 mi. That is exactly twice the 5K.

Not quite. The marathon is 42.195 km, which is 26.21876 miles. 26.2 is the common rounded figure.

A mile is longer. One mile is 1.609344 km, so a kilometer is only about 62 percent of a mile.

100 km/h is 62.14 mph. Divide any km/h figure by 1.609344 to read it in mph.

Divide by 8 and multiply by 5. 40 km becomes 25 mi against a true 24.85 mi, about 0.6 percent high.

Five minutes per kilometer is 8:03 per mile. Multiply the per-km pace by 1.609344.

Courses are measured on the shortest legal line, and runners rarely hold it. Weaving round other runners and corners adds distance to a GPS track.

The UK uses miles and miles per hour on road signs. Its speed limits are set in mph by law.

Yes. The kilometer is 1,000 meters everywhere, and the international mile has been the same in the US and UK since 1959.

No. The conversion runs in your browser and nothing is sent to our servers. Anything you choose to Save stays in this browser only.

• Mile = 1.609344 km and km/h to mph conversion factors (NIST SP 811, Appendix B.8).
• Mile = 1,760 yards and yard = 0.9144 m in UK law (Weights and Measures Act 1985, Schedule 1, legislation.gov.uk).
• The US survey foot, the survey mile and their retirement in 2023 (NIST Office of Weights and Measures).
• Standard road race distances and course measurement rules (World Athletics Book of Rules, C2.1 Technical Rules, Part VII Road Races).
• UK speed limits set in miles per hour (Road Traffic Regulation Act 1984, Schedule 6, legislation.gov.uk).