Running Pace & Split Calculator

Turn a goal time into a race-day plan — target pace, a split table for every kilometre or mile, equivalent race times, and training paces. Enter a goal to build a plan, or a recent result to see what it predicts. Everything is computed in your browser.

Format: 1:45:00 or 45:00

Units
Split strategy
Target pace
4:59/km
Finish time
1:45:00
Distance
Half

Split table (km)

even splits
SplitPace/kmSplit timeElapsed
14:594:594:59
24:594:599:57
34:594:5914:56
44:594:5919:54
54:594:5924:53
64:594:5929:52
74:594:5934:50
84:594:5939:49
94:594:5944:48
104:594:5949:46
11 · halfway4:594:5954:45
124:594:5959:43
134:594:591:04:42
144:594:591:09:41
154:594:591:14:39
164:594:591:19:38
174:594:591:24:36
184:594:591:29:35
194:594:591:34:34
204:594:591:39:32
214:594:591:44:31
21.10 km4:590:291:45:00

Equivalent race times

Riegel model — estimates, not promises.

5K
22:50 · 4:34/km
10K
47:35 · 4:46/km
Half Marathon (your input)
1:45:00 · 4:59/km
Marathon
3:38:55 · 5:11/km

Training paces

Derived transparently from your result.

Recovery(Marathon effort + 25%)
6:29/km
Easy / long run(Marathon effort + 15%)
5:58/km
Marathon(~Marathon effort (Riegel))
5:11/km
Threshold / tempo(~15K effort (Riegel))
4:53/km
Interval / VO₂(~3K effort (Riegel))
4:26/km

How the pace calculator works

Your target pace is simply your goal time divided by the race distance. From there the split table shows the exact clock time you should hit at every kilometre or mile. Choose an even, negative, or positive split and the table keeps the total on your goal time while ramping the pace across the race.

Equivalent race times and training paces

Equivalent finish times use the Riegel model, T2 = T1 × (D2/D1)^1.06, a widely used endurance formula. Training paces are anchored to Riegel-equivalent efforts at reference distances — for example threshold pace is close to your 15K effort and interval pace is close to your 3K effort — with easy and recovery paces set as labelled multipliers of marathon effort. Treat all of these as transparent starting points and override them with your own recent results and how you feel.

Privacy

Nothing is uploaded. All calculations run in your browser, and shareable links only encode the inputs you choose.

Frequently asked questions

How is running pace calculated?

Pace is your goal time divided by the distance. This tool shows it per kilometre and per mile, then builds a split table so you know the target time at every marker.

What is a negative split?

A negative split means running the second half faster than the first. Choose negative or positive splits and a spread, and the table keeps the total exactly on your goal time.

How accurate are the equivalent race times?

Equivalent times use the Riegel model (T2 = T1 × (D2/D1)^1.06), a widely used endurance formula. They are estimates that assume similar training and course profiles — always override with your own recent results.

Where do the training paces come from?

Each zone is anchored to a Riegel-equivalent effort at a reference distance (for example threshold ≈ your 15K effort) or a labelled multiplier of marathon effort, so every number is explainable rather than a black box.