Running pace calculator

Goal time in, pace out. Or pace in, finish time out. Then see what your 5K says about your 10K and half.

Pace ↔ time

Pace / km6:24
Finish32:00

9.4 km/h · 10:18 per mile

Even-pace splits
PointClock
1 km6:24
2 km12:48
3 km19:12
4 km25:36
Finish32:00

Race time predictor

RacePredictedPace /kmPace /mi
5K32:006:2410:18
10K1:06:436:4010:44
Half marathon2:27:126:5911:14
Marathon5:06:557:1611:42

Predictions assume you've trained for the longer distance. For a first half marathon, add 5–10% to be safe.

Explainer: why you can't just double your 5K time

Pete Riegel's 1977 formula predicts T₂ = T₁ × (D₂ / D₁)k. With k = 1 you'd hold the same pace forever (the grey bars). Real runners slow as distance grows, so k is a bit above 1. Drag it and watch the prediction stretch.

5K
base
10K
+2:43
Half marathon
+12:11
Marathon
+36:52

Riegel's own data put k at about 1.06 for trained runners. Beginners, who haven't built much endurance yet, often slow more (1.08–1.10), which is why the table's advice is to pad your half marathon goal. The extra time on the right is what fatigue “costs” over simply holding your pace.

Using pace as a first-timer

Pace is a result, not a target, for most of your training. Easy runs go by feel (see the talk test on the 10K plan page). Pace matters in two places: planning a realistic race goal, and not starting too fast on the day.

A practical trick: work out your goal pace here, then run the first kilometre or mile 10–15 seconds slower than it. The crowd will pull you along faster than you think.

Common beginner paces

Pace per kmPer mile5K10KHalf
5:008:0325:0050:001:45:29
5:308:5127:3055:001:56:02
6:009:3930:001:00:002:06:35
6:3010:2832:301:05:002:17:08
7:0011:1635:001:10:002:27:41
7:3012:0437:301:15:002:38:14
8:0012:5240:001:20:002:48:47
9:0014:2945:001:30:003:09:53

Questions first-timers ask

How do I calculate my running pace?

Divide your finish time by the distance. A 5K in 32:00 is 32 ÷ 5 = 6.4 minutes, which is 6:24 per kilometre, or 10:18 per mile.

What is a good pace for a beginner?

Any pace at which you can hold a conversation on easy runs. For many beginners that is somewhere between 6:30 and 8:30 per kilometre (10:30–13:40 per mile), and walk breaks are fine.

How accurate is the race time predictor?

The Riegel formula is usually within a few percent when you have trained properly for the longer race. It tends to be optimistic for beginners stepping up to a half marathon, so add 5–10% for a first attempt.

Should I run even splits in my first race?

Roughly even, or slightly faster in the second half, is the safest plan. Starting too fast is the most common first-race mistake and costs far more time later than it saves early.