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Running math, done instantly

Pace Calculator

Enter any two of pace, time and distance and get the third the moment you type — with your speed in km/h and mph. Need splits and race predictions? Tap Go advanced.

Your run

Distance km
km
Time
Hours
:
Minutes
:
Seconds
Pace km
Minutes
:
Seconds
Your pace
/km
Enter distance and time.
Tip: switch I want to calculate to solve for whichever value you're missing.
Result
/km ·

How to calculate running pace

Pace ties together three numbers: the distance you run, the time it takes, and your pace — the minutes and seconds you spend on each kilometre or mile. Know any two and the third is fixed.

Pace = Time ÷ Distance TIME = PACE × DISTANCE · DISTANCE = TIME ÷ PACE

Run 10 km in 50 minutes and your pace is 50 ÷ 10 = 5:00 per km. Flip it around — hold 5:00/km for a marathon and you'll finish in about 3 h 30 m. The calculator above solves in whichever direction you need and shows your speed in km/h and mph as you go.

Pace, speed and splits

Pace and speed are two views of the same thing: 5:00 per km is exactly 12 km/h. Runners usually think in pace, cyclists and treadmills in speed, so the tool shows both. Open Go advanced for a full split table — the time you'd pass each kilometre or mile marker — and switch it to negative or positive splits to plan a fast finish or a hard start.

Worked example

Goal: a sub-2-hour half marathon (21.1 km).

2:00:00 ÷ 21.1 = 5:41 per km (about 9:09 per mile, 10.5 km/h). The equivalent-times table shows that same effort is roughly a 28:26 10K and a 58:36 10-miler.

Common race distances

Tap a preset to load the exact distance, then enter a target time to see the pace behind it.

RaceDistance
Mile1.609 km
5K5.0 km
10K10.0 km
Half marathon21.10 km
Marathon42.20 km

Even vs negative splits

  • Even — the same pace throughout; the simplest race plan and easy to hold.
  • Negative — start a little slower and speed up; often the strongest way to race a long distance.
  • Positive — start faster and ease off; useful for downhill-start courses or hard efforts.

In the advanced view, pick a strategy and set how many seconds to spread from the first split to the last — your overall time stays the same, only the distribution changes.

Kilometres or miles

Switch distance and pace units independently. Enter a distance in miles while reading pace in min/km if that's how your watch is set — the maths stays exact either way.

Common questions

How do I calculate running pace?

Pace is your time divided by your distance. Run 10 km in 50 minutes and your pace is 50 ÷ 10 = 5:00 per km. Enter any two of pace, time and distance above and the calculator works out the third instantly, plus your speed in km/h and mph.

What is a good running pace?

It varies by runner and distance. Many recreational runners cover a 5K around 6–7 min/km (about 10–11 min/mile); a sub-25-minute 5K is roughly 5:00/km. Enter a goal time to see the pace it needs, then check the equivalent finish times for other distances.

How do I convert pace to speed?

Speed in km/h is 60 divided by your pace in min/km — so 5:00/km is 12 km/h. For miles, 60 divided by your min/mile pace gives mph. The calculator shows both automatically whenever pace is known.

What are negative splits?

Running the second half faster than the first. In the advanced view choose Negative and set the seconds to spread; the split table starts slower and finishes faster while keeping your overall time the same.

How do I predict a race time from my pace?

Enter a distance and your target time or pace, then open the advanced view. The equivalent finish times table applies that pace to the mile, 5K, 10K, half and marathon so you can see what it means at other distances.