How it works
min/km = min/mile × (1000 ÷ 1609.344); speed = distance ÷ time
The international mile is defined as exactly 1609.344 meters, so converting a per-mile pace to per-kilometer is one multiplication by 1000 ÷ 1609.344, roughly 0.621371 — 8:00 per mile times that factor lands near 4:58 per kilometer. Going the other direction you divide: 5:00 per kilometer works out to about 8:03 per mile. Speed just flips the fraction — divide 60 by the minutes-per-unit figure, so a 6:00 mile is 10.00 mph and 16.09 km/h. Values are carried in meters and seconds right up to display, which means whichever of the four numbers you type, the other three round consistently instead of drifting a second apart.
Sources
- International mile definition NIST Handbook 44 / international yard-and-pound agreement (1959): 1 international mile = 1609.344 metres exactly.
- Pace–speed relationship Kinematics: average speed = distance ÷ time; pace is its inverse, expressed as time per unit distance.
FAQ
What exactly can I convert here?
Any single pace or speed. Pick “Pace” and type a min/mi or min/km figure, or pick “Speed” and type mph or km/h — the output lists all four equivalents side by side. That covers the everyday cases: translating a metric training plan for a miles watch, decoding a treadmill console, or checking a race cutoff expressed as a speed.
Is the conversion an estimate or exact?
Exact, in both directions. The mile is pinned at 1609.344 meters by definition, so pace-to-speed and mile-to-km conversions are pure arithmetic with no model behind them — the only rounding is in the seconds displayed on screen.
Why does my watch show a slightly different converted pace?
Apps and watches round to whole seconds at different points in their math, so a converted figure can land a second away from the one computed here. This tool converts from the exact mile definition and rounds once, at display; when two sources disagree by a second, that rounding order is almost always the reason.
Should the min/mile number always be bigger than min/km?
For the same effort, yes. A mile is 1.609344 km, so it takes about 61% longer to cover than a kilometer — 8:00 per mile and 4:58 per kilometer are one identical speed despite looking far apart. If your per-mile figure ever comes out smaller, a unit got swapped somewhere.
What treadmill speed matches my running pace?
Set the mode to Speed, enter the mph from the console, and read the min/mi line — 7.5 mph is an 8:00 mile. Keep in mind the console reports belt speed: at a given setting the effort can feel different from road running, so treat the converted pace as the machine’s claim rather than a measure of how hard you worked.
Where does 1609.344 come from?
The 1959 international yard and pound agreement fixed the yard at 0.9144 m, which makes the statute mile exactly 1609.344 m. The calculator uses that exact value rather than a shortened 1.61, so a chain of conversions stays exact instead of accumulating error.
Unit conversion has no fitness model inside it — the four figures are one motion restated, exact to the definition of the mile. How any pace feels on a given day still depends on you and the conditions; this page is general reference material, not training prescription or medical advice.