DistanceWise

Kilometers to Miles Converter

Divide by 1.609344 — or multiply by 0.621 for a fast estimate.

kilometres (km)

miles (mi)

kilometres → miles

5 km = 3.107 mi

Type in either box — the other updates to match.

kilometres to miles conversion table

Includes 21.1 km (half marathon) and 42.2 km (full marathon).

kilometres (km)	miles (mi)
1 km	0.621 mi
2 km	1.243 mi
5 km	3.107 mi
10 km	6.214 mi
15 km	9.321 mi
21.1 km	13.111 mi
25 km	15.534 mi
42.2 km	26.222 mi
50 km	31.069 mi
100 km	62.137 mi
200 km	124.274 mi
500 km	310.686 mi
1,000 km	621.371 mi

What you entered

kilometres: 5 km

1
Conversion factor
1 km = 0.6214 mi= × 0.6214
2
Multiply by the value
5 × 0.6214= 3.1069 mi

Result

miles: 3.107 mi

5 km equals 3.107 mi, because one kilometre is 0.621 mi.

Race distances and journeys in kilometres and miles

Dividing by 1.609344 converts kilometres to miles. These are the standard race distances plus common journeys.

What it is	km	mi
5K race	5	3.107
Everest height	8.849	5.499
10K race	10	6.214
Daily commute	20	12.427
Half marathon	21.0975	13.109
Marathon	42.195	26.219
Motorway speed, 100 km/h	100	62.137
Paris to London	344	213.752

Multiply by 0.62 for a quick estimate - 100 km is about 62 miles, which the table confirms at 62.137. The Fibonacci approximation works here too, running the other way: 13 km is about 8 miles, 21 km about 13. Note that the marathon distance of 42.195 km is exact by definition and 26.219 miles is the derived figure, which is why the imperial number is untidy.

Converting kilometres to miles means dividing by 1.609344, or equivalently multiplying by 0.621371. The factor is exact because the mile is defined in terms of the metre through the foot, so the only imprecision is in how many decimals you display. A useful mental shortcut is that a kilometre is roughly six-tenths of a mile, so multiplying by 0.6 gets you within about three and a half per cent — close enough for reading a road sign or estimating a journey.

The most frequent reason for this conversion is athletics. Race distances worldwide are set in metric, so runners in the United States and United Kingdom regularly translate them into the miles they train in. The standard set converts to 3.107 miles for a 5K, 6.214 for a 10K, 13.109 for a half marathon and 26.219 for a marathon, and the reference table on this page includes the exact race distances rather than round numbers for that reason.

Travel is the other common context. Most of the world signs roads in kilometres, so visitors from the US or UK converting distances and speeds is a routine part of trip planning. It matters more than it seems: misreading a 100 km/h limit as though it were 100 mph is a substantial error in the dangerous direction, since 100 km/h is only about 62 mph.

A neat mathematical curiosity makes rough conversion easy without any arithmetic. Consecutive Fibonacci numbers approximate the mile-to-kilometre ratio closely, because the golden ratio of about 1.618 is very near the true factor of 1.609. So 8 km is roughly 5 miles, 13 km is roughly 8 miles, and 21 km is roughly 13 miles — which is why a half marathon of 21 km lands so neatly on 13 miles.

The Fibonacci shortcut

Consecutive Fibonacci numbers approximate this conversion because the golden ratio (1.618) is close to the true factor (1.609). So 8 km ≈ 5 miles, 13 km ≈ 8 miles, 21 km ≈ 13 miles. It's why a 21 km half marathon lands almost exactly on 13 miles.

Speed conversions matter for safety

A 100 km/h limit is about 62 mph, not 100. Misreading metric speed signs as imperial is an error in the dangerous direction, and it's a common mistake for drivers newly abroad. Convert speeds deliberately rather than by feel.

Frequently asked questions

How many miles are in a kilometre?

About 0.621371 miles, found by dividing 1 by 1.609344. Multiplying kilometres by 0.6 is a quick mental estimate accurate to roughly three and a half per cent.

What is 21 km in miles?

21 km is 13.05 miles, and the official half marathon distance of 21.0975 km is 13.109 miles. That closeness to a round 13 is a coincidence of the Fibonacci-like ratio between the two units.

What is 100 km/h in mph?

About 62.1 mph. The same factor applies to speeds as to distances, since both are just kilometres per unit time converted to miles per the same unit.

Which countries still use miles?

The United States and the United Kingdom are the main ones for road distances, along with a handful of smaller territories. Almost everywhere else signs roads in kilometres, which is why this conversion comes up so often when travelling.