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About the running pace calculator
Training for a 5K, a 10K or your first marathon? Pace is the number runners live by: minutes per kilometre or minutes per mile. This calculator works it out both ways:
- Find my pace — from a distance and a time ("I ran 5 km in 28 minutes")
- Find my finish time — from a distance and a pace ("Marathon at 5:30 per km")
It also shows your speed in km/h and mph, and predicted times for the other race distances, so you can set a realistic goal.
How to use it
- Choose Find my pace or Find my finish time
- Type the distance — or tap 5K, 10K, Half marathon or Marathon
- Type your time (like 28:00 or 1:52:30) — or your pace (like 5:30)
- Read your pace, finish time, speed and predictions
Pace chart
| Pace per km | Pace per mile | 5K | 10K | Half marathon | Marathon |
|---|---|---|---|---|---|
| 4:00 | 6:26 | 20:00 | 40:00 | 1:24:23 | 2:48:47 |
| 4:30 | 7:14 | 22:30 | 45:00 | 1:34:56 | 3:09:53 |
| 5:00 | 8:03 | 25:00 | 50:00 | 1:45:29 | 3:30:58 |
| 5:30 | 8:51 | 27:30 | 55:00 | 1:56:02 | 3:52:04 |
| 6:00 | 9:39 | 30:00 | 1:00:00 | 2:06:35 | 4:13:10 |
| 6:30 | 10:28 | 32:30 | 1:05:00 | 2:17:08 | 4:34:16 |
| 7:00 | 11:16 | 35:00 | 1:10:00 | 2:27:41 | 4:55:22 |
How the predictions work
The predicted times use Riegel's formula, which runners have used since the 1970s:
T2 = T1 × (D2 ÷ D1)^1.06
The 1.06 means you slow down a little as the distance grows. A 28-minute 5K predicts about 58:23 for 10K, 2:08:48 for a half marathon and 4:28:33 for a marathon. The longer the jump, the more the prediction depends on training — a marathon needs the long runs.
Tips for pacing a race
- Start a little slower than goal pace — the first kilometres feel easy and tempt you to go too fast.
- Aim for even splits — the same pace each kilometre is the fastest way to finish.
- Use a pace band with your split times, or set a pace alert on your watch.
- Hills and heat slow everyone down: plan 10–20 seconds per km slower.
Frequently asked questions
How do I calculate my running pace?
Divide your time by the distance. 28 minutes for 5 km is 28 ÷ 5 = 5:36 per km (9:01 per mile).
What pace do I need for a 4-hour marathon?
About 5:41 per km, or 9:09 per mile. Choose Find my pace, tap Marathon and type 4:00:00.
What is a good 5K time?
It depends on age and experience. Many beginners run 30–40 minutes; regular runners often finish in 22–28 minutes. Improving your own time is what counts.
How do I type the time?
As hours:minutes:seconds or minutes:seconds — 1:52:30 or 28:00. On a phone you can use a dot instead: 28.00.
Is the marathon prediction accurate?
It is a fair guess if you have trained for the distance. Many runners are a few minutes slower in their first marathon than the formula says.
Good to know
- A half marathon is 21.0975 km (13.1 miles); a marathon is 42.195 km (26.2 miles)
- Your last run is saved in this browser
- Nothing you type is sent anywhere
Related tools
- Stopwatch — time your runs
- Interval Timer — run/walk and interval training
- Miles to km — distance conversion
- Km to Miles — distance conversion
- Countdown to Date — days until race day
