Convert Miles to Kilometers
Turn miles on a US road sign, race entry or fitness tracker into metric kilometers. Helpful when planning travel in metric countries or comparing pace data across apps.
1 mi = 1.6093 km
One mile equals exactly 1.609344 kilometres. To convert miles to kilometres, multiply the mile value by 1.609344 — so 5 mi = 8.05 km and 26.2 mi = 42.16 km. This factor is exact rather than measured: the 1959 international yard and pound agreement defined the yard as precisely 0.9144 m, which fixes the mile at 1,609.344 m by definition. For mental arithmetic, multiplying by 1.6 is accurate to within 0.6 percent, so a 60 mph speed limit is about 96 km/h and a 10 mi run is 16 km. A neater trick uses the Fibonacci sequence: consecutive terms approximate the ratio, so 5 mi ≈ 8 km, 8 mi ≈ 13 km and 13 mi ≈ 21 km. The distinction to watch is the nautical mile, which is 1,852 m exactly and used in aviation and shipping — roughly 15 percent longer than the statute mile meant here.
Quick reference: miles to kilometers
| Miles | Kilometers |
|---|---|
| 0.5 | 0.805 km |
| 1 | 1.609 km |
| 3 | 4.828 km |
| 5 | 8.047 km |
| 10 | 16.093 km |
| 13.1 | 21.082 km (half marathon) |
| 26.2 | 42.165 km (marathon) |
| 50 | 80.467 km |
| 100 | 160.934 km |
How do you convert miles to kilometers?
Formula: kilometres = miles × 1.609344 • A 26.2-mile marathon → 26.2 × 1.609344 = 42.16 km, which is why the official distance is quoted as 42.195 km (the marathon is defined in metric, and 26.2 mi is the rounded imperial version). • A 70 mph US interstate limit → 70 × 1.609344 = 112.65 km/h, just above the 110 km/h limit common on European motorways. • A 3,000-mile US coast-to-coast drive → 3,000 × 1.609344 = 4,828 km, useful when a rental agreement caps mileage in kilometres.
When and why people use miles to kilometers
The most frequent everyday need is travel. Road signs, rental-car odometers and fuel-economy figures switch units at most borders, and a driver crossing from the US into Canada or from the UK into France needs the conversion to read speed limits and distance markers correctly. Running is the other big one. Race distances are defined in metric almost everywhere — 5 km, 10 km, the 21.0975 km half marathon and the 42.195 km marathon — while American training plans and treadmills are usually calibrated in miles. Converting lets you compare a pace in minutes per mile against one in minutes per kilometre without guessing. Aviation and marine navigation add a wrinkle worth knowing: both use the nautical mile, which is 1,852 m exactly and roughly 15 percent longer than the statute mile used on roads. A distance quoted in a flight plan is not the same mile as a distance on a highway sign.
Common mistakes to watch for when converting miles to kilometers
The common shortcut is multiplying by 1.6, which is fine for a mental estimate but drifts noticeably over distance: at 100 miles the shortcut gives 160 km against a true 160.93 km, a gap of nearly a kilometre. The second mistake is confusing statute and nautical miles — a 500 nautical-mile flight leg is 926 km, not the 805 km you would get using the road mile. The third is assuming the factor is an approximation that might be refined later; it is not. Since 1959 the mile has been defined in terms of the metre, so 1.609344 is exact and will not change. A fourth trap is the US survey mile, a legacy unit about 3 mm longer per mile, formally deprecated at the end of 2022 but still present in some older land records.
How to estimate miles to kilometers in your head
Multiply by 1.5 and then add a tenth of the original. For 60 miles: 1.5 × 60 = 90, plus 6 = 96 km, against a true 96.6. That is within 0.6% and easy to do while driving. The Fibonacci relationship also runs backwards: 5 mi ≈ 8 km, 8 mi ≈ 13 km, 13 mi ≈ 21 km. Runners find these particularly handy because they map onto common race distances almost exactly — a 13-mile half marathon is 21 km. The crude 'add two thirds' method is quicker but drifts about 3.5% high. Over a 500-mile drive that is a 28 km overestimate, which matters if you are working out whether you can reach a destination on one tank. For anything where the number feeds into a fuel or time calculation, use the exact 1.609344.
Miles to Kilometers FAQ
How many kilometres is a mile?
- Exactly 1.609344 km. The figure is fixed by definition under the 1959 international yard and pound agreement, not measured experimentally.
Is multiplying by 1.6 accurate enough?
- For a rough estimate, yes. But the error compounds — at 100 miles the shortcut is off by nearly a full kilometre, and at 1,000 miles by more than nine.
Is a 10-mile race longer than 15 km?
- Yes. 10 miles is 16.09 km, so a 10-mile race is about 1.1 km longer than a 15 km race.
Why is the marathon 42.195 km and not exactly 26.2 miles?
- The marathon is defined in metric at 42.195 km. Converting that back gives 26.2188 miles, which is normally rounded to 26.2 in imperial listings.
What is a nautical mile?
- 1,852 m exactly — about 15% longer than a statute mile. It is used in aviation and at sea, and is a different unit from the mile on road signs.
What was the US survey mile?
- A legacy unit about 3 mm longer per mile, used in historic land surveys. NIST deprecated it at the end of 2022 in favour of the international mile.
How do I convert a pace rather than a distance?
- Invert the factor: divide minutes per mile by 1.609344 to get minutes per kilometre. An 8:00 mile is about a 4:58 kilometre.
Is anything I type sent to a server?
- No. The conversion runs in JavaScript inside your browser tab and no value is transmitted or logged.
Last updated:
Sources: 1959 international yard and pound agreement; NIST Special Publication 811 on unit conversion; NIST announcement deprecating the US survey foot, effective 31 December 2022.