What Is My Running Pace?

One run, four numbers, and they're all the same fact

You ran 5K in 28:30. Depending on who's asking, that's:

• 5:42 per kilometre
• 9:10 per mile
• 10.53 km/h
• 6.54 mph

Nothing is estimated here — pace is time divided by distance, and speed is distance divided by time. Same run, described four ways, because race results, treadmills, watches and training plans stubbornly refuse to agree on units.

Enter the distance, pick the unit, and put the time in as hours, minutes and seconds — the seconds matter, because a pace rounded to the nearest minute is no use for pacing anything.

The arithmetic

5 km in 28:30 — that's 1,710 seconds.

Per kilometre:

1,710 s ÷ 5 km = 342 s = 5:42 per km

Per mile. A mile is 1.609344 km exactly, so 5 km is 3.107 miles:

1,710 s ÷ 3.107 = 550 s = 9:10 per mile

Speed:

3.107 miles ÷ 0.475 hours = 6.54 mph

Notice the pace is worked out in whole seconds first and then split into minutes and seconds. Doing it the other way round — taking the minutes off and converting the remainder — lets a pace of 9.999 minutes display as "9:60".

The thing your average is hiding

Here's what makes this worth more than a unit conversion.

Almost nobody runs an even pace. The overwhelmingly common pattern is going out too fast and fading — and a fast-then-fade run produces exactly the same average as a controlled even one.

They don't finish in the same time, though. The fade almost always costs more than the fast start gained. So two runners with an identical 9:10 average can have had completely different days, and only one of them ran well.

That's the real use of this number: run the next one deliberately even and compare. If your first mile feels comfortable and slightly boring, you've probably got it right.

Don't train at this pace

This is the most common mistake in recreational running, and it's worth being blunt about.

The pace this calculator gives you for a race is a race pace. Most of your training is supposed to be comfortably conversational — noticeably slower — with only a small share of genuinely hard running.

Running every session at race pace is how people plateau, stop enjoying it, and pick up injuries. Use this figure to pace an event and to track progress over months. Not as the speed for Tuesday's easy run.

Why your watch disagrees with the race result

Your watch said 13.4 miles. The race was a half marathon: 13.1.

Neither is broken. GPS measures the line you actually ran; a course is measured along the shortest legal route. Weaving through a crowded field, running wide on every bend and losing signal under trees all add up, and a watch commonly reads a few percent long over that distance.

Enter the official distance here. Your watch is telling you how far you personally travelled, which is a genuine and mildly irritating fact about your day.

The distances, in both units

Event	Miles	Kilometres
5K	3.11	5
10K	6.21	10
Half marathon	13.1094	21.0975
Marathon	26.2188	42.195

Enter whichever unit the event uses and switch the dropdown — you get both sides either way.

A marathon is defined as 42.195 km exactly — "26.2 miles" is the rounded imperial version, and it's short by about 30 metres. Entering 26.2 makes your pace read about a third of a second per mile quicker than you ran, which doesn't change a thing in practice. The exact figures are in the table because they cost nothing to be right about, not because the rounding will hurt you.

For the treadmill, use the speed

Treadmills are set in miles or kilometres per hour, not minutes per mile, so use the speed figure rather than the pace.

Two caveats worth knowing: the belt is doing some of the work for you, and most machines in most gyms are not calibrated. The same number will feel different outdoors, usually harder.

Print the race pace card, write your target splits on it before the day, and carry it. Deciding your pace on the start line is deciding it too late.

This is arithmetic on numbers you enter — it makes no assessment of your fitness and predicts nothing. Decisions about training load, injury and whether to run at all are for you and a qualified professional, particularly if you're new to running, returning from injury, pregnant, or managing a heart, lung or joint condition. Not medical advice.