How to Calculate Running Pace

Pace is the simplest calculation on this site — plain arithmetic with no estimation involved. What makes it worth a guide is not the formula but the conversions and the planning you can do with it.

Pace and speed

pace  = time ÷ distance    (minutes per km or per mile)
speed = distance ÷ time    (km/h or mph)

They express the same thing inverted. Runners generally think in pace — minutes per kilometre — because race targets and training prescriptions are given that way. Cyclists generally think in speed.

For 5 km in 30 minutes:

pace  = 30 ÷ 5 = 6.0 min/km  →  6:00 per km
speed = 5 ÷ 0.5 h = 10.0 km/h

Our Pace Calculator converts between them.

Reading the decimal correctly

One reliable source of confusion: a pace of 6.5 min/km is 6:30 per km, not 6 minutes 50 seconds. The decimal is a fraction of a minute, not seconds.

To convert, multiply the fractional part by 60:

5.25 min/km → 0.25 × 60 = 15 s → 5:15 per km
5.75 min/km → 0.75 × 60 = 45 s → 5:45 per km

The calculator displays minutes and seconds directly, which avoids the trap entirely.

Kilometres and miles

Pace per mile is always the larger number, since a mile is longer than a kilometre — 1.609 km, to be precise.

For a 10 km run in 50 minutes:

Distance: 10 km = 6.214 miles
Pace:     5:00 per km  =  8:02 per mile
Speed:    12.0 km/h

A rough mental conversion: multiply your per-km pace by about 1.6 to get per-mile. A 5:00/km pace is close to 8:00/mile, which is a handy pair to remember.

Using pace to plan a race

The most practical use is projecting a finish time, or working backward from a target:

finish time = pace × distance

For a marathon (42.195 km) at 5:00 per km, that is about 3 hours 31 minutes. Working the other way, a sub-4-hour marathon needs roughly 5:41 per km.

That backward calculation is the useful one — it converts a vague goal into a specific pace you can practise in training and hold on race day.

What the number doesn't account for

The calculation is exact, but a real run is not run on a flat line in still air. Hills, wind, heat, terrain, and fatigue all affect what pace is achievable, and none of them appear in time ÷ distance.

This is worth remembering when comparing runs. A 5:30/km on a hilly route in heat may represent considerably more effort than a 5:15 on a flat track in cool weather. Pairing pace with heart rate zones gives a fuller picture of effort than pace alone.

The bottom line

Pace is time divided by distance, and speed is its inverse. Watch the decimal — 6.5 min/km means 6:30 — and multiply by about 1.6 to convert per-km to per-mile. Use it to convert a goal time into a pace you can train. Run the numbers on the Pace Calculator.