km to miles

How do you use the km to miles converter?

Type a distance in the Kilometers box and the Miles box updates as you type; the line underneath reads it back, for example “10 km = 6.214 mi”. There is no Convert button and nothing is sent to a server. Step by step:

1. Enter the km value in the left box. It starts at 10 so you can see the format.
2. Read the miles result on the right and in the sentence below, shown to three decimals.
3. Tap swap (⇄) for the reverse. The same tool on miles to km leads with miles.
4. Copy the result to paste into a training log, a text or homework.
5. Open “All units” to see the same distance in meters, feet, yards and nautical miles, and edit any of them.
6. Scan the quick table under the inputs for 1 to 1,000 km without typing.

Need a speed rather than a distance? Use km/h to mph; the factor is the same, but the unit describes how fast, not how far.

What is the formula for km to miles?

miles = km ÷ 1.609344, which is the same as km × 0.621371. The divisor is exact by definition. NIST’s SI guide (SP 811, Appendix B.8) lists the mile as exactly 1.609344 km, because the international foot has been fixed at 0.3048 m since 1959 and a mile is 5,280 feet. NIST retired the slightly different US survey foot on January 1, 2023, so there is now one mile for every purpose in the US.

miles = km ÷ 1.609344  ·  miles = km × 0.621371

How many miles is a 5K, 10K, half marathon and marathon?

A 5K is 3.11 miles, a 10K is 6.21 miles, a half marathon is 13.11 miles and a marathon is 26.22 miles. These are the km to miles conversions people search for most, because US races are named in kilometers but US runners train in miles. The marathon (42.195 km) and half marathon are the distances World Athletics uses for road world records, as listed by AIMS, the body whose measurers certify courses.

Want your own finish time? The pace calculator turns any pace in min/mile or min/km into a 5K, 10K or marathon time. Note that real courses are measured along the shortest legal line, so your GPS watch will usually show a little more than 3.11 miles for a 5K.

km to miles conversion table (1 to 1,000 km)

Every common distance converted with the exact factor and rounded to two decimals. Use the left pair for walks, runs and city trips, and the right pair for road trips and flights.

Two landmarks make the rest easy: 8 km is almost exactly 5 miles (4.97) and 160 km is almost exactly 100 miles (99.42). Scale from those and you will rarely be more than a few percent off.

How do you convert km to miles in your head?

Multiply by 6 and drop the last digit: 40 km → 240 → 24 miles (exact 24.85). It reads about 3.5% low, which is fine for “how far is the next town”. For closer answers, pick one of these:

• Halve three times, then × 5 (that is × 5/8). 80 km → 40 → 20 → 10 → 50 miles. Exact: 49.71. About 0.6% high.
• Half plus a tenth, plus a fiftieth. 100 km → 50 + 10 + 2 = 62 miles. Exact: 62.14. Within 0.2%.
• Fibonacci pairs read backward. 8 km ≈ 5 mi, 13 ≈ 8, 21 ≈ 13, 34 ≈ 21, 55 ≈ 34, 89 ≈ 55. The miles to km page explains why this works.

Where will you see km instead of miles?

On road signs in Canada, Mexico, India and almost every country outside the US and UK, on race bibs, and on many trail and park maps. Canada switched its road signs to kilometers in the late 1970s, according to The Canadian Encyclopedia, so a sign reading “Toronto 120” means 120 km, or 74.6 miles. In India, highway milestones and Google Maps directions are in km; a 300 km drive is 186.4 miles.

Odometers and trip meters. A car sold in a km country counts kilometers. If a used import shows 80,000 on the odometer, that is 49,710 miles. Our GPS odometer can show a trip in either unit, which is handy in a rental car whose display you cannot switch.

Fitness apps and treadmills. Many treadmills and watches default to km outside the US. A 5 km treadmill session is 3.11 miles; 1 km splits of 6:00 are 9:39 per mile. If you also need speed, the speed, distance and time calculator does both units.

Nautical charts are different. Boats and aircraft use nautical miles: 1 nautical mile is exactly 1,852 m, or 1.15 statute miles. The All units panel shows nautical miles alongside km and miles.

Common km to miles mistakes

The most common slip is multiplying by 1.609 instead of dividing, turning 10 km into a bogus 16 miles. Miles are always the smaller number.

• Rounding the factor too early. 0.6 instead of 0.621371 loses 21 miles over 1,000 km. Convert first, round last.
• Treating “K” as a thousand miles or meters. In running, “5K” means 5 kilometers, never 5,000 miles; 5,000 meters, yes.
• Mixing up distance and speed. “100 km” is how far (62.14 miles); “100 km/h” is how fast (62.14 mph). Same number, different unit; see km/h to mph.
• Using GPS track length as the official race distance. GPS traces wander and usually read long; certified course length is what counts.

About this page

Every number on this page was computed with the site’s tested distance code (src/lib/distance.ts), which uses the exact NIST definition of the mile, and rounded only for display. Race distances come from AIMS and World Athletics; see the sources below. Written by Izhar Ahmad Danish. For your live distance and speed, open the GPS speedometer on the homepage.