Kilometres to Miles Converter
1 km = 0.6213712 miles. Type in either box.
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Five eighths, near enough
One kilometre is 0.6213712 miles — almost exactly five eighths. That approximation is good to within half a per cent and is the easiest mental route: divide by eight and multiply by five.
1 km = 0.6213712 mi
A quicker version: multiply by six and drop the last digit. 80 km × 6 = 480 → 48 miles, against a true 49.7.
For runners, the anchors are 5 km = 3.11 miles, 10 km = 6.21 miles, a half marathon = 13.11 miles and a marathon = 26.22 miles.
The kilometre
A thousand metres, and the unit of road distance almost everywhere outside the United States and the United Kingdom. A brisk walk covers a kilometre in about twelve minutes.
It is about five eighths of a mile, which gives a handy mental conversion: multiply kilometres by 6 and drop the last digit.
The mile
Exactly 1,609.344 metres, or 5,280 feet. The odd number comes from the Roman mille passus, a thousand double-paces, later reconciled with the furlong so that eight furlongs made a mile.
It is the road-distance unit of the United States and the United Kingdom, and the reason both countries quote fuel economy and speed limits in figures the rest of the world has to convert.
The working, step by step
Every line updates with whatever you type above. The point is the method, which is the same for any pair of units in this family.
The same quantity, two different numbers
One physical amount, read off two scales. The tick marks do not line up, and the gap between them is the conversion factor made visible.
How much is that?
A number is easier to judge next to something familiar.
Your turn
Reading a method and being able to use it are different things. Answer within half a per cent and it counts as correct.
Score: 0 of 0
How to use this converter
- Type into either box. The other side updates as you go; there is no button to press.
- Swap the direction with the button between the boxes, carrying your value across.
- Set the decimals if the default is more or less precision than you need.
- Copy the answer with its unit, ready to paste.
- Use the shortcut buttons for the values that come up most often.
- Share the result. The address bar tracks what you type, so the link you copy opens on the same number.
Common uses and tips
Where length conversions come up
- Height. Quoted in feet and inches in Britain and America, and in centimetres nearly everywhere else. 5 ft 10 in is 178 cm.
- Buying things online from another market, where the dimensions are in units your tape measure does not have.
- DIY and building, where materials come in metric sizes and older plans are in imperial.
- Screens, tyres and pipes, which stay in inches worldwide even in fully metric countries.
- Running and cycling, where race distances are metric and training apps may report either.
Numbers worth carrying
- 1 inch = 2.54 cm exactly. Everything imperial in this family descends from it.
- 1 foot = 30.48 cm, twelve inches.
- 1 yard = 0.9144 m, a little shorter than a metre.
- 1 mile = 1.609 km, and 1 km = 0.621 mile.
- A metre is about 39.37 inches, or 3 ft 3 in.
Mental shortcuts
Kilometres to miles: multiply by six and drop the last digit. 80 km × 6 = 480, drop the digit for 48 miles, against a true 49.7.
Miles to kilometres: add sixty per cent. 50 miles plus 60 % is 80 km, against a true 80.5.
Centimetres to inches: divide by 2.5 and take off a little. Dividing by 2.5 gives an answer about 1.6 % high.
Mistakes worth avoiding
- Feet and inches are not decimal. 5.5 feet is 5 ft 6 in, not 5 ft 5 in. Multiply the decimal part by twelve.
- Do not use length factors for area or volume. A foot is 0.3048 m, but a square foot is 0.0929 m² and a cubic foot 0.0283 m³.
- Check which mile. A nautical mile is 1,852 m, about 15 % longer than a statute mile.
Values people look up most
Each one opens the converter with the number already in it.
- 1 km to mi
- 2 km to mi
- 3 km to mi
- 5 km to mi
- 8 km to mi
- 10 km to mi
- 15 km to mi
- 20 km to mi
- 21.1 km to mi
- 25 km to mi
- 30 km to mi
- 40 km to mi
- 42.2 km to mi
- 50 km to mi
- 60 km to mi
- 80 km to mi
- 100 km to mi
- 150 km to mi
- 200 km to mi
- 1,000 km to mi
Quick reference
| Kilometres | Miles |
|---|---|
| 1 km | 0.621371 mi |
| 5 km | 3.106856 mi |
| 10 km | 6.213712 mi |
| 21.1 km | 13.110932 mi |
| 42.2 km | 26.221864 mi |
| 50 km | 31.06856 mi |
| 100 km | 62.137119 mi |
| 1,000 km | 621.371192 mi |
Questions people ask
What is the formula for km to miles?
Multiply by 0.6213712.
What is 100 km in miles?
62.14 miles.
How many miles is a 5K?
3.11 miles.
Is five eighths a good approximation?
Yes. It gives 0.625 against a true 0.6214 — about 0.6 % high.