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1km to Miles Converter
Our 1km to miles converter turns kilometers into miles — and miles back into kilometers — in one click. Type any distance, use the swap button to change direction, and get an exact answer for running, driving, cycling, or travel planning.
Common distances
| Kilometers | Miles | What it is |
|---|---|---|
| 1 km | 0.621 miles | A short walk |
| 5 km | 3.107 miles | A popular fun run (5K) |
| 10 km | 6.214 miles | A 10K race |
| 21.098 km | 13.109 miles | A half marathon |
| 42.195 km | 26.219 miles | A full marathon |
How it works
Most of the world measures distance in kilometers, but the United States measures it in miles. That split shows up everywhere: a rental car in France lists its range in kilometers, a race in London is a 10K, a fitness app may log your run in kilometers, and a road trip in Texas is measured in miles. To move between the two systems you need one fixed number, the conversion factor.
One kilometer equals exactly 0.621371 miles. One mile equals exactly 1.609344 kilometers. These numbers never change — they are definitions, not estimates — so every conversion on this page is exact to the decimal places shown.
To convert kilometers to miles, multiply by 0.621371. To go the other way, multiply miles by 1.609344 — or divide kilometers by 0.621371, which gives the same answer. A quick mental shortcut is that 5 miles is about 8 kilometers, and 10 kilometers is about 6.2 miles, but for race times, fuel planning, or a road trip, use the exact factor in the converter above.
Runners use this conversion constantly. A 5K race is 5 kilometers, or 3.107 miles. A 10K is 6.214 miles. A half marathon is 21.098 kilometers, or 13.109 miles, and a full marathon is 42.195 kilometers, or 26.219 miles — the distance run in Boston, New York, and Chicago every year. Cyclists and drivers meet the same problem abroad: a speed limit of 100 km/h is about 62 mph, and a 400 km drive in Europe is about 249 miles.
Worked example
Alex from Austin is training for the Chicago Marathon and his training plan is written in kilometers. This week it calls for a 42.195 km long run — the full marathon distance — and he wants to know how many miles that is.
Step 1: Write down the distance — 42.195 km.
Step 2: Use the conversion factor — 1 km = 0.621371 miles.
Step 3: Multiply: 42.195 × 0.621371 = 26.21875.
Step 4: Round to three decimal places — 26.219 miles.
That is the exact result this converter gives for 42.195 km: 26.219 miles. The same steps work for the simple case too: 1 km × 0.621371 = 0.621371 miles, so a single kilometer is just over six-tenths of a mile.
FAQ
How many miles is 1 km?
1 kilometer equals 0.621371 miles. So a 1 km walk is just over six-tenths of a mile.
How many miles is a marathon in kilometers?
A marathon is 42.195 kilometers, which equals 26.219 miles — the standard marathon distance run in Boston, New York, and Chicago.
How do I convert miles back to kilometers?
Multiply miles by 1.609344. For example, 10 miles × 1.609344 = 16.093 kilometers. Use the swap button on this page to convert either direction.
Why does the US use miles instead of kilometers?
The United States kept the imperial system for road distances, while most of the world uses the metric system. That is why American road signs, speed limits, and running races are in miles, and European ones are in kilometers.