Running pace calculator — pace, finish time or distance

How to use the pace calculator

1. Under Solve for, choose Pace, Finish time or Distance.
2. Choose the Distance unit: km or miles.
3. Fill in the two fields that appear: Distance, Time (h:mm:ss or mm:ss) and/or Pace per unit (mm:ss).
4. Read the answer at the top, plus Speed, the pace in the other unit, and the Race times at this pace table.

What it does and when to use it

Runners juggle three numbers: how far, how long and how fast. Know any two and the third follows. This calculator handles all three directions, so you can:

• find the pace you ran from a distance and a time,
• set a target finish time for a race and see the pace it needs,
• or see how far a timed run at a set pace takes you.

It also converts between per-kilometre and per-mile pace, which helps when a training plan uses one unit and your watch uses the other. The race table shows what your pace means at the four common road distances, a quick way to set realistic goals. For quick unit conversion only, the running pace converter is simpler. To pair pace with effort, the heart rate zone calculator gives training zones, and the VO2 max calculator estimates fitness from a 12-minute run.

How it works

The calculator turns times into seconds and then uses:

• Pace = time ÷ distance
• Time = pace × distance
• Distance = time ÷ pace
• Speed = distance ÷ (time in hours), in km/h or mph

To switch units it uses 1 mile = 1.609344 km. Race times multiply your pace by each race distance: 5 km, 10 km, 21.0975 km (half marathon) and 42.195 km (marathon). Results are rounded to the nearest second.

Worked examples

These figures come from the calculator’s own function.

A 50-minute 10K. Solve for Pace, 10 km in 50:00. Pace 5:00 per km, speed 12 km/h, which is 8:03 per mile. At that pace the table shows a 25:00 5 km, a 1:45:29 half marathon and a 3:30:59 marathon.

A marathon at 5:00 per km. Solve for Finish time, 42.195 km at 5:00. Finish time 3:30:59.

An hour at 8-minute miles. Solve for Distance, unit miles, time 1:00:00, pace 8:00. Distance 7.5 mi at 7.5 mph, or 4:58 per km. The race table predicts 24:51 for 5 km.

Limits and tips

• Even pace assumed. Real races have hills, turns and fatigue. Most people slow over longer distances, so a 10K pace usually cannot be held for a marathon.
• Times past 24 hours still work, shown as hours beyond 24.
• The table is a projection, not a race prediction model.
• If you have a health condition or are new to running, check with a doctor before training hard. The calculation runs in your browser.