A pace conversion chart solves the small, constant friction of running in mixed units: a plan written in minutes per mile, a watch set to kilometres, a treadmill in miles per hour. It lays the equivalents side by side so a pace in one unit reads instantly as the same pace in the others, without arithmetic mid-run.
Min per mile to km: the constant between them
A pace conversion chart rests on one fixed ratio: a mile is 1.609 kilometres, so a per-mile pace divides by that to become a per-kilometre pace, and multiplies back the other way. Running pace conversion is nothing more than applying that constant, but doing it in your head at mile five is exactly when it goes wrong, which is what the chart is for.
Pace and speed are reciprocals, so mph to minutes per mile is one division
The other conversion runners need is pace to speed: minutes per mile and miles per hour are reciprocals, so mph to minutes per mile is a division into sixty. A pace conversion chart holds that too, which is what lets you set a treadmill in miles per hour to match a pace written per mile, or read a 5K mile pace as a treadmill speed.
Using one number everywhere
The value of a pace conversion chart is consistency: pick the unit you think in, and convert everything else to it once rather than repeatedly. A runner who trains in minutes per mile can convert a metric race target once, run the pace they know, and never do the arithmetic again mid-effort, which is where conversions usually fail.
Treadmill speed to pace km, when the watch is metric and the belt is not
Treadmill speed to pace km is the two constants applied in order: minutes per mile is sixty divided by the belt speed in miles per hour, and a per-mile pace divides by 1.609 to read as minutes per kilometre. So 8 mph is a 7:30 mile and a 4:40 kilometre, while 10 km/h is a 6:00 kilometre and a 9:39 mile. The chart holds both columns at once, which is the whole point for a runner on an imperial belt wearing a metric watch: otherwise that is two conversions in your head while running.
Questions people ask about pace conversion chart
How do you convert min/mile to min/km?
Divide the per-mile pace by 1.609, since a mile is 1.609 kilometres; the pace conversion chart holds the result so you do not do it mid-run.
How do I convert treadmill mph to pace, and treadmill speed to mile pace?
Both are the same division: minutes per mile is sixty divided by the belt speed in miles per hour, so 8 mph reads as a 7:30 mile. Reverse it to set the belt from a pace you already train at.
Why use a running pace chart at all?
To avoid arithmetic under fatigue; convert your race target to the unit you train in once, and run the pace you already know.
Is a treadmill pace conversion the same read in both directions, and are treadmill pace conversions exact?
Yes to both. Speed and pace are reciprocals, so sixty divided by the belt speed gives the pace in minutes per mile and sixty divided by that pace gives the speed back, with nothing lost either way. The arithmetic is exact; what a conversion cannot tell you is how the same pace feels on a belt rather than on the road.