Miles to Kilometers Converter
Convert miles to kilometers instantly. Enter any value and get the result. Includes a conversion table and the exact formula.
| Miles | Kilometers |
|---|
How to convert miles to kilometers
Enter your value
Type the number of miles you want to convert into the left box. The result in kilometers appears instantly in the right box. You can also type into the right box to convert in the other direction.
Use the swap button
Click the ⇄ Swap button to reverse the conversion — Kilometers to Miles. Your current value carries across so you don't have to re-enter anything.
Why 1.60934 and where it comes from
The mile and kilometer both measure distance, but they come from completely different origins — the mile from Roman marching paces (mille passus, "a thousand paces"), the kilometer from the French metric system's division of the Earth's meridian. Since 1959, the international mile has been fixed at exactly 1,609.344 metres by treaty between the US, UK and four other countries, which is where the 1.60934 conversion factor (rounded to five decimal places) comes from. Before that agreement, the US and UK each used a very slightly different mile.
Miles to km for runners and drivers
Race distances
Marathon: 26.2 miles = 42.195 km. Half marathon: 13.1 miles = 21.0975 km. 10K road race: 6.214 miles. 5K: 3.107 miles. Parkrun (5 km) is run as a fixed metric distance worldwide, so converting to miles (3.11) is only needed for comparing to a mile-based training plan.
Driving abroad
UK and US road signs use miles; almost everywhere else in the world uses kilometers. A UK motorway speed limit of 70 mph is about 113 km/h — useful to know before hiring a car in Europe, where speedometers and satnavs are set to km/h.
Quick mental estimate
For a fast approximation without a calculator, multiply miles by 1.6, or add 60% to the mile figure. It's not exact (1.60934 vs 1.6), but it's close enough for a quick read of a road sign or a pace chart.
Why does the UK still use miles?
Partial metrication
The UK began metricating in 1965 but road distances and speed limits were never converted — miles remain the legal unit for road signage in the UK, even though the country uses metric units for almost everything else (weights in kg, short distances in metres, temperature in °C).
Ireland switched, the UK didn't
The Republic of Ireland converted its road signs from miles to kilometers in January 2005. The UK has debated the same switch repeatedly but has not implemented it, partly due to the cost of replacing millions of road signs and vehicle speedometers.
The US never metricated its roads
The US officially adopted the metric system for trade in 1975, but road signage, speed limits and everyday distance measurement remain in miles, making the US and UK the main countries where a miles-to-km converter is genuinely needed for everyday travel.
Add 60% to miles for a quick kph mental estimate. UK motorway limit (70 mph) = 113 kph. US interstate limit (typically 65-75 mph) = 105-121 kph. Most European motorway limits are 120-130 kph.
| Miles | Kilometers |
|---|---|
| 0.25 | 0.4023 |
| 0.5 | 0.8047 |
| 1 | 1.609 |
| 2 | 3.219 |
| 3 | 4.828 |
| 5 | 8.047 |
Frequently asked questions
How do I convert miles to kilometers?
To convert miles to kilometers, multiply by 1.60934. Or use the calculator above for instant results.
How many kilometers are in 1 mile?
1 mile equals 1.60934 kilometers.
Is the miles to kilometers converter free?
Yes, the miles to kilometers converter is completely free with no sign-up required, no downloads, and it works offline once the page has loaded.
Why is a mile 1.60934 km and not a rounder number?
The figure comes from the international mile being fixed at exactly 1,609.344 metres under the 1959 international yard-and-pound agreement between the US, UK, Australia, Canada, New Zealand and South Africa. 1.60934 km is that same figure rounded to five decimal places for everyday use.
How many kilometers is a marathon?
A marathon is 26.2 miles, which is 42.195 kilometers exactly. A half marathon is 13.1 miles (21.0975 km), and a 10K road race is 6.214 miles.
Is 100 km more or less than 100 miles?
100 km is less than 100 miles. 100 km equals 62.14 miles, while 100 miles equals 160.934 km — a mile is longer than a kilometer, so the same number of miles always covers more ground than the same number of kilometers.
What speed is 70 mph in km/h?
70 mph is approximately 112.65 km/h, commonly rounded to 113 km/h. This is the UK's motorway speed limit expressed in metric terms, useful when driving abroad or using a satnav set to km/h.