Convert any distance from miles into kilometres, with the working shown, the answer also given in kilometres and metres, and a miles to kilometres table. One mile is exactly 1.609344 km.
Multiply the distance in miles by the exact conversion factor 1.609344.
Kilometres: Miles × 1.609344
1 mi = 1.609344 km
1 km = 0.621371 mi
0.01 mi = 0.016093 km
0.1 mi = 0.160934 km
1 mi = 1.609344 km
2 mi = 3.218688 km
3 mi = 4.828032 km
4 mi = 6.437376 km
5 mi = 8.04672 km
6 mi = 9.656064 km
7 mi = 11.265408 km
8 mi = 12.874752 km
9 mi = 14.484096 km
10 mi = 16.09344 km
20 mi = 32.18688 km
30 mi = 48.28032 km
40 mi = 64.37376 km
50 mi = 80.4672 km
60 mi = 96.56064 km
70 mi = 112.65408 km
80 mi = 128.74752 km
90 mi = 144.84096 km
100 mi = 160.9344 km
This calculator converts a distance given in miles into kilometres by multiplying by 1.609344. That number is exact by definition, so the result carries no conversion error at all. A 240-mile drive, for example, becomes about 386 km.
Indians meet miles most often when travelling or studying abroad, reading car reviews and specifications from the US or UK, following international running or cycling plans, or watching sport where distances such as the marathon's 26.2 miles are quoted. Converting into kilometres makes those numbers feel real, because you can compare them with the familiar Mumbai to Pune or Delhi to Jaipur distances you already know.
1. Write the distance in miles.
2. Multiply by 1.609344: Kilometres = Miles × 1.609344.
3. For a mental estimate, multiply by 1.6, or by 8 and divide by 5. This is about 0.6% low.
4. If you need metres, multiply the kilometres by 1000.
5. For speeds, the same factor turns miles per hour into kilometres per hour.
The mile is defined in terms of the yard, and the yard has been fixed at exactly 0.9144 metres by international agreement since 1959. A statute mile is 1,760 yards, so it equals 1,760 × 0.9144 = 1,609.344 metres exactly. Dividing by 1000 gives 1.609344 km. Because both sides are defined, not measured, the factor has no rounding hidden inside it. This is also why the reverse factor, 0.621371..., is a long decimal while this one terminates.
A speed in miles per hour converts with the same multiplier, because the hour stays the same: 65 mph is about 104.6 km/h. Fuel economy is trickier. American figures in miles per US gallon need both the distance factor and the gallon, which is 3.785 litres, while British figures use the larger imperial gallon of 4.546 litres. So 30 mpg in the US is about 12.8 km/l, but 30 mpg in the UK is about 10.6 km/l.
Because the factor is exact, how much you round is a choice about usefulness. For a road trip, a whole number of kilometres is plenty. For a running race, organisers measure to the metre, so the marathon's 26.2188 miles becomes 42.195 km. When you convert a rounded mileage like '26.2 miles', remember the input itself is rounded, and the kilometre figure can be no more precise than that.
Rohan is planning a 240-mile drive between two cities during his first year at university in the US and wants to picture it in kilometres.
Answer: Kilometres 386.24256
Multiplying by 0.621 instead of 1.609, which shrinks the distance when it should grow.
Using 1.6 for long trips, where the 0.6% shortfall adds up to several kilometres.
Converting US miles-per-gallon figures with only the mile factor and forgetting the gallon.
Treating nautical miles on a flight map as statute miles; a nautical mile is 1.852 km.
Planning driving distances and fuel stops on trips to the US or UK.
Converting speed limits from mph into the km/h you are used to.
Translating international marathon and cycling plans into kilometres.
Understanding car, bike or aircraft specifications quoted in miles.
How many kilometres are in a mile?
Exactly 1.609344 km, or 1,609.344 metres.
How many km is 10 miles?
10 × 1.609344 = 16.09344 km, which is 16 km and 93.44 metres.
How do I convert mph to km/h?
Multiply by 1.609344. For example, 60 mph = 96.56 km/h and 70 mph = 112.65 km/h.
Is this conversion exact?
Yes — a mile is defined as exactly 1,609.344 metres, so this conversion is exact, not an approximation.