Km to Miles Converter
Convert kilometers to miles instantly with this free km to miles converter. Type any km distance and get the exact miles, look up common values like 5 kilometers to miles or 50 km to miles, and check speed with km per hour to mph. A ready-made table covers running races (5K, 10K, half marathon, full marathon) and common road trip distances.
1 Kilometer = 0.621371 Mile
Running race distances: km to miles
Every major road race distance converted, with typical finish time ranges for reference.
| Race | Kilometers (km) | Miles | Average finish time |
|---|---|---|---|
| 1 mile race | 1.609 km | 1.0 mi | 4 to 8 minutes |
| 5K | 5 km | 3.107 mi | 20 to 40 minutes |
| 8K | 8 km | 4.971 mi | 35 to 60 minutes |
| 10K | 10 km | 6.214 mi | 45 to 75 minutes |
| 15K | 15 km | 9.321 mi | 1:10 to 2:00 hours |
| Half Marathon | 21.0975 km | 13.109 mi | 1:45 to 3:00 hours |
| 30K | 30 km | 18.641 mi | 2:30 to 4:00 hours |
| Marathon | 42.195 km | 26.219 mi | 3:30 to 6:00 hours |
| 50K Ultra | 50 km | 31.069 mi | 5:00 to 10:00 hours |
| 100K Ultra | 100 km | 62.137 mi | 10:00 to 20:00 hours |
Speed conversion: km/h to mph
Common speed limits and running paces converted between metric and imperial.
| km/h | mph | Context |
|---|---|---|
| 10 km/h | 6.2 mph | Jogging pace (6 min/km) |
| 15 km/h | 9.3 mph | Fast running (4 min/km) |
| 30 km/h | 18.6 mph | Urban road limit (many countries) |
| 50 km/h | 31.1 mph | City speed limit |
| 80 km/h | 49.7 mph | Rural road limit |
| 100 km/h | 62.1 mph | Motorway / highway |
| 120 km/h | 74.6 mph | German Autobahn advisory |
| 130 km/h | 80.8 mph | France / Spain motorway limit |
What this converter includes
Instant conversion
Type any km value and miles updates without pressing a button.
Race distance table
5K, 10K, half marathon, and marathon, all converted with race context.
Speed reference
Common km/h speeds shown alongside their mph equivalents.
Swap direction
Switch from miles to km just as easily with one click.
All length units
Also converts meters, cm, feet, inches, yards, and nautical miles.
No account needed
Completely free, no signup, works offline once loaded.
When you need km to miles
Running and race training
US runners use miles. Most race distances are set in km. Know exactly how far your 10K or half marathon is in miles before race day.
Road trips and navigation
GPS apps in some countries show km while road signs in the US and UK show miles. Convert quickly when crossing borders or using foreign maps.
Cycling and fitness apps
Strava, Garmin, and Wahoo let you track in km or miles. Convert past efforts if you switch units mid-training.
Car specs and fuel economy
European car manuals list range and efficiency in km. US drivers want miles per gallon and total miles. Convert fuel economy figures accurately.
Hiking and trail planning
National park trail maps in many countries use km. Trail apps aimed at US hikers show miles. Convert before you head out.
Aviation and nautical
Flight distances often mix km and nautical miles. Speed is measured in knots. Convert distances for international flight planning.
About kilometers and miles
How to convert km to miles
Converting kilometers to miles takes one simple step: multiply the number of kilometers by 0.621371. That single factor handles every conversion, whether you are working out a short jog or a long road trip. To go the other way and convert miles to kilometers, multiply the miles by 1.60934 instead. The converter at the top of this page does both directions for you, but knowing the method means you can also check the math by hand or estimate on the move.
The km to miles formula
1 mile = 1.60934 km (exactly 1609.344 meters). So the km to miles formula is miles = km / 1.60934, or equivalently, miles = km x 0.621371. The reverse formula, mile to kilometer, is km = miles x 1.60934. For quick mental math, multiply km by 0.6. That underestimates by about 3.5%, but it is good enough for rough trip planning. For example, 10 kilometers to miles gives 6 miles as a mental estimate, while the exact answer is 6.21 miles.
What is 1 km in miles and 1 mile in km?
1 km in miles is 0.621371 miles, a little under two-thirds of a mile. Going the other way, 1 mile in km is 1.60934 kilometers, or roughly one and three-fifths of a kilometer. These two numbers are reciprocals of each other, so if you remember one you can always recover the other. Most everyday questions about distance come down to scaling these two base values up or down.
Common km to miles conversions
Some distances come up again and again, so it helps to know them by heart. 5 kilometers to miles is 3.107 miles, the length of a standard 5K race. 10 kilometers to miles is 6.214 miles, double the 5K. 15 km to miles is 9.321 miles, and 20 kilometers to miles is 12.427 miles. 50 km to miles is 31.069 miles, a popular ultra distance. Scaling up, 100 km is 62.137 miles. Each of these is simply the kilometer figure multiplied by 0.621371, so you can apply the same step to any value the converter is not preloaded with.
Converting miles back to kilometers
The mile to kilometer direction is just as common, especially for US runners and drivers reading metric maps. To convert miles to km, multiply by 1.60934. So 1 mile is 1.609 km, 5 miles is 8.047 km, 10 miles is 16.093 km, and 26.2 miles (a marathon) is 42.165 km. If you ever forget which factor to use, remember that a mile is longer than a kilometer, so converting miles to km should always give a bigger number, and converting km to miles should always give a smaller one.
Converting km per hour to mph
Speed converts with the very same factor as distance, because miles per hour and kilometers per hour share the same time unit. To convert kilometer per hour to miles per hour, multiply the km/h value by 0.621371. So converting km per hour to mph, 50 km/h becomes 31.1 mph, 80 km/h becomes 49.7 mph, and 100 km to mph works out to 62.1 mph, a typical highway speed. To reverse it, multiply mph by 1.60934: 60 mph is 96.6 km/h. The speed table above lists the most common limits and running paces side by side.
Km to miles for running race distances
Most official road races are measured in kilometers, but US runners usually think in miles, so converting between the two is part of race-day planning. A 5K is 3.107 miles, a 10K is 6.214 miles, a 15K is 9.321 miles, and a half marathon (21.0975 km) is 13.109 miles, often rounded to 13.1. A full marathon is 42.195 km, or 26.219 miles, the famous 26.2. Knowing these conversions helps you set a realistic pace, because a target like a 5 minute per kilometer pace translates to roughly an 8 minute per mile pace.
The Fibonacci trick for km to miles
If you know the Fibonacci sequence (1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89...), you can use consecutive numbers to approximate km to miles conversions. 8 km is close to 5 miles (exact: 4.97). 13 km is close to 8 miles (exact: 8.08). 21 km is close to 13 miles (exact: 13.05). This works because the ratio of consecutive Fibonacci numbers converges toward the golden ratio, which is close to 1.618 (and 1 km = 0.621 miles, the reciprocal of 1.609).
Why does the US still use miles?
The US uses miles because it inherited its measurement system from British imperial practice before the metric system was widely adopted. The mile dates to Roman times (mille passuum: 1,000 double-steps). Converting road infrastructure, signs, and habits costs enormous political and financial capital. Metric conversion has never been mandated for everyday use in the US despite repeated legislative efforts, which is why a reliable km to miles converter stays useful for travelers, runners, and drivers.
Kilometers in scientific and aviation contexts
Science worldwide uses the metric system, including km for distance. Aviation uses a mix: horizontal distances in nautical miles (1 nmi = 1.852 km), altitude in feet, and speed in knots. This is an aviation-specific historical convention maintained for international air traffic consistency. Space distances are measured in km, AU (astronomical units), and light-years.
1 kilometer equals 0.621371 miles. A quick approximation: multiply km by 0.6. For distances over 10 km, this is close enough for most planning purposes.
Multiply the kilometers by 0.621371. For example, 10 km x 0.621371 = 6.21 miles. To go from miles to km, multiply by 1.60934. Our converter does both instantly.
A 5K race is 5 kilometers, which equals 3.107 miles. The 5K is the most popular road race distance in the world, and most runners complete it in 20 to 40 minutes.
A 10K is exactly 10 kilometers (6.214 miles). It is twice the distance of a 5K and a common stepping stone before half-marathon training.
A half marathon is 21.0975 km, which equals 13.1094 miles. It is usually rounded to "13.1 miles" or "21.1 km" in race materials.
A marathon is 42.195 km, which equals 26.219 miles (commonly cited as 26.2 miles). The distance was standardized at the 1908 London Olympics.
100 km equals 62.14 miles. Ultra-marathon runners use 100 km as a common race distance, also called a 100K or "a century" in cycling.
Multiply mph by 1.60934. So 60 mph = 96.56 km/h. To go from km/h to mph, multiply by 0.621371. A car doing 100 km/h is doing 62.1 mph.
1 mile equals 1.60934 kilometers. The mile is the primary road distance unit in the US and UK. Most other countries use kilometers for road distances and speed limits.
The US inherited the mile from British imperial measurement. The mile dates back to Roman times (mille passuum: 1,000 double-paces). When the UK and most countries switched to the metric system in the 19th and 20th centuries, the US did not mandate the change. Road signs, speed limits, and distances in the US remain in miles.
1 km in miles is 0.621371 miles, which is a little under two-thirds of a mile. For a quick estimate, multiply kilometers by 0.6. The exact factor is 0.621371, so 1 kilometer rounds to about 0.62 miles.
1 mile in km is 1.60934 kilometers, or exactly 1609.344 meters. Because a mile is longer than a kilometer, converting miles to km always gives a larger number. Multiply any mile value by 1.60934 to get kilometers.
5 kilometers to miles is 3.107 miles. This is the length of a standard 5K race, the most popular road race distance in the world. Multiply 5 by 0.621371 to get the exact result.
10 kilometers to miles is 6.214 miles. It is the distance of a 10K race and twice the length of a 5K. The quick mental estimate is 6 miles, which is close enough for casual planning.
15 km to miles is 9.321 miles. This matches the 15K race distance, a common stepping stone between a 10K and a half marathon. Multiply 15 by 0.621371 for the exact figure.
20 kilometers to miles is 12.427 miles. That is just shy of a half marathon, which is 21.0975 km or 13.109 miles. For a fast estimate, 20 km is roughly 12.4 miles.
50 km to miles is 31.069 miles. This is a popular ultramarathon distance, often called a 50K. It is about 5 miles longer than a standard 42.195 km marathon.
To convert kilometer per hour to miles per hour, multiply the km/h value by 0.621371. So 50 km/h is 31.1 mph and 80 km/h is 49.7 mph. To reverse it, multiply mph by 1.60934 to get km/h.
100 km to mph is 62.1 mph, a common highway speed. The conversion uses the same factor as distance: multiply km/h by 0.621371. A car cruising at 100 km/h is moving at about 62 miles per hour.