Convert miles and kilometres instantly. This free miles to km converter switches either direction using the exact factor (1 mile = 1.609344 km), with metres and a quick conversion table.
Enter a distance and choose the direction. One mile equals exactly 1.609344 kilometres, so the conversion is exact (not an approximation).
A quick mental shortcut: multiply miles by 1.6 for km, or by about 8/5. To go the other way, multiply km by 0.62 (roughly 5/8) for miles.
What This Miles to Km Converter Does
Convert miles to kilometres, or kilometres back to miles, using the exact internationally defined conversion factor. The result also shows the equivalent in metres and a rounded approximate figure for quick reference.
The Exact Conversion Factor
One mile is defined as exactly 1.609344 kilometres, derived from the same 1959 international agreement that standardized the inch, foot, and yard. This is an exact figure, not a rounded approximation.
For example, 5 miles converts to exactly 8.04672 km.
The Quick Mental Shortcut
A common shortcut multiplies miles by 1.6 (or roughly 8/5) for a quick km estimate, and multiplies km by 0.62 (roughly 5/8) to go the other way. This is close enough for casual use, but the exact factor should be used for anything measured or reported precisely.
Why Miles and Kilometres Still Coexist
Most of the world uses kilometres for road distances and speed limits, while the US, UK, and a handful of other countries still commonly use miles. This split is why converting between the two remains a frequent, practical need for travelers, runners, and drivers alike.
Common Uses for This Conversion
This conversion comes up often for road trip planning, running and cycling distances, speed limit signs when driving abroad, and comparing race distances (like a 5K versus a 5-mile run) that are reported in different unit systems.
Why the Mile Has Such an Unusual Exact Figure
Unlike the inch (2.54 cm) or the foot (0.3048 m), the mile’s exact conversion factor of 1.609344 km looks like an odd, non-round number. This is simply a consequence of the mile being defined as exactly 5,280 feet, and each of those feet being fixed at exactly 0.3048 metres – the result of multiplying those two exact figures together produces the seemingly arbitrary 1.609344.
Comparing Race Distances Across Unit Systems
Runners often compare a 5K (5 kilometres, about 3.1 miles) against a 5-mile race (about 8.05 km) – two genuinely different distances that sound deceptively similar when only the number “5” is mentioned without its unit. Always check which unit a race distance is quoted in before assuming it matches a familiar distance.
How to Use the Miles to Km Converter
- Choose a direction: miles to km, or km to miles.
- Enter your distance, decimals included.
- Review the result along with the metres and quick approximate figures.
Converting a shorter length instead? See our Feet to Meters Converter.
Using the Miles to Km Converter for Running, Driving and Travel
A miles to km converter earns its keep where two systems meet: race plans, road trips abroad and fitness apps that default to different units.
- Race distances: a marathon is 42.195 km, about 26.2 miles.
- Pace, not just distance: divide minutes per mile by 1.609344 to get minutes per kilometre. A 9:00 mile pace is roughly 5:35 per km.
- Speed limits: before driving in a km/h country, run your usual mph speeds through the miles to km converter and remember an anchor, such as 60 mph being about 97 km/h.
The 8/5 mental shortcut is fine for road signs, but it runs about 0.6% low, so 100 miles comes out as 160 km instead of 160.93 km. Use the miles to km converter when the numbers go into a training log or an expense claim.
Nautical miles are a different unit, exactly 1,852 m, so don’t feed sea or air distances into a miles to km converter built for statute miles. The mile article on Wikipedia explains the different miles and why a miles to km converter uses 1.609344.