Convert kilometres to miles
Kilometres to miles, exactly. Includes the true half-marathon and marathon distances, plus metres, feet and yards for every value.
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miles = kilometres ÷ 1.609344 = 5 ÷ 1.609344 = 3.1069 mi 1 km = 0.621371 mi
| kilometres | miles |
|---|---|
| 1 km | 0.6214 mi |
| 2 km | 1.2427 mi |
| 3 km | 1.8641 mi |
| 5 km | 3.1069 mi |
| 8 km | 4.9710 mi |
| 10 km | 6.2137 mi |
| 15 km | 9.3206 mi |
| 20 km | 12.4274 mi |
| 21.0975 km | 13.1094 mi |
| 25 km | 15.5343 mi |
| 30 km | 18.6411 mi |
| 42.195 km | 26.2188 mi |
| 50 km | 31.0686 mi |
| 80 km | 49.7097 mi |
| 100 km | 62.1371 mi |
| 120 km | 74.5645 mi |
| 130 km | 80.7783 mi |
Divide by 1.609344
Kilometres to miles is a division by the exact figure 1.609344, or a multiplication by 0.621371192. Both give the same answer; the division is easier to remember and harder to mistype. 100 km is 62.14 miles, 10 km is 6.21 miles, and 1 km is 0.621 miles.
Three mental shortcuts, ranked
| Trick | How | Error |
|---|---|---|
| Multiply by 0.6 | 100 km → 60 mi | 3.4% low — fine for a rough idea |
| Fibonacci | Adjacent Fibonacci numbers: 8 km ≈ 5 mi, 13 km ≈ 8 mi, 21 km ≈ 13 mi | Under 0.5% — uncannily good |
| Halve and add a tenth of the half twice | 100 → 50 → 55 → 60.5, then a nudge | About 2% low |
The Fibonacci coincidence works because the golden ratio, 1.618, is within 0.6% of 1.609344. It is the best mental conversion in any unit system and it costs nothing to remember.
Driving in a metric country
- 50 km/h = 31 mph — the standard European urban limit
- 80 km/h = 50 mph
- 100 km/h = 62 mph
- 120 km/h = 75 mph — common motorway limit in Spain, Italy and Ireland
- 130 km/h = 81 mph — French autoroute in the dry
Fuel economy does not convert the same way. Litres per 100 km is an inverse measure, so you cannot scale it directly into miles per gallon; you have to invert as well as convert, and the gallon differs between the US (3.785 L) and the UK (4.546 L).
Race distances the other way
A 5K is 3.11 miles, a 10K is 6.21, a half marathon is 13.11 and a full marathon is 26.22. If your watch is set to miles and the course is measured in kilometres, expect the markers to drift out of step with your splits: by 20 km you are 12.43 miles in, not 12.5.
Elevation, and why it is usually feet
Even in fully metric countries, aviation altitude is in feet and many cycling and running apps default to feet for climb. A 1,000 m ascent is 3,280.8 ft. The extras panel on this page shows feet alongside miles for exactly that reason — climb and distance are often quoted in different systems on the same screen.
Questions
How many miles is 5 km?
3.10686 miles — commonly written as 3.1. A 10K is 6.21 miles and a half marathon (21.0975 km) is 13.109 miles.
Is the "multiply by 0.6" trick good enough?
For a rough head count, yes: 0.6 is within 3.5% of the true 0.621371. Over a marathon that error is nearly a mile and a half, so use the real figure when it matters.
How do I convert a pace rather than a distance?
Pace inverts, so minutes per kilometre become minutes per mile by multiplying by 1.609344, not dividing. A 5:00/km pace is 8:03/mile.
Why does my car show a different conversion?
Speedometers are legally allowed to over-read and never under-read, so the displayed speed is typically 1–3% above the true speed in either unit. The arithmetic here is exact; the dashboard is deliberately conservative.