Marathon calculator
Enter your goal time or the pace you can hold. Get your pace, checkpoint times and a gel plan for the 42.195 km.
How the calculation works
Your pace is the finish time divided by 42.195 km. The checkpoint times assume you run that pace from start to finish, so each is the pace multiplied by the distance to that point. If you enter a pace, the finish time is the pace multiplied by 42.195 km.
The gel plan spaces gels so that the carbohydrate in each one adds up to your hourly target. A 25 g gel at a target of 60 g per hour is one gel every 25 minutes. The first gel comes after 30 minutes and the last at least 15 minutes before the finish.
Marathon pace chart
These are the paces for common finish times. Enter your own goal for exact checkpoints and a gel plan.
| Finish time | Pace per km | Pace per mile | Halfway | Speed (km/h) | Gels (60 g/h, 25 g) |
|---|---|---|---|---|---|
| 3:00:00 | 4:16 | 6:52 | 1:30:00 | 14.07 | 6 |
| 3:30:00 | 4:59 | 8:01 | 1:45:00 | 12.06 | 7 |
| 4:00:00 | 5:41 | 9:09 | 2:00:00 | 10.55 | 8 |
| 4:30:00 | 6:24 | 10:18 | 2:15:00 | 9.38 | 10 |
| 5:00:00 | 7:07 | 11:27 | 2:30:00 | 8.44 | 11 |
Fuelling in a marathon
Most runners use up their stored carbohydrate after roughly 30 to 35 km, which is why many feel the effort rise late in the race. Taking carbohydrate on the way delays that. The amount that works is individual and your stomach needs practice, so try your plan, your brand of gel and your drinks in long training runs well before race day.
This plan is a general guide. It is not medical advice. If you have a health condition such as diabetes, or you are unsure how much to take, ask a doctor or a sports dietitian.
Examples
Frequently asked questions
What pace do I need for a 4-hour marathon?
5:41 per kilometre or 9:09 per mile, held evenly. The halfway point is at 2:00:00.
How many gels do I need for a marathon?
It depends on your finish time and how much carbohydrate you aim for per hour. For a 4-hour marathon at 60 g per hour with 25 g gels the plan has 8 gels, one about every 25 minutes. Use the calculator to match your own numbers.
How much carbohydrate should I take per hour?
Sports nutrition guidance for events longer than about 2.5 hours is up to 60 g per hour, and up to 90 g per hour for runners who have trained their gut to tolerate it. The right amount is personal, so practise in training.
Why do the gels start after 30 minutes and stop before the finish?
The body's own stores cover the first stretch, and a gel taken in the last 15 minutes would not reach the muscles in time. The calculator leaves those periods out, so the intake it plans is slightly below the target.
Should I run an even pace?
An even pace is a safe plan on a flat course. For a faster second half see the split calculator, which lets you choose a negative split.
Related calculators
Sources
- World Athletics, Technical Rules – the marathon is 42.195 km
- Jeukendrup, A. (2014). A step towards personalized sports nutrition, carbohydrate intake during exercise. Sports Medicine, 44 (Suppl 1), S25–S33.
- Thomas, D. T., Erdman, K. A., Burke, L. M. (2016). Position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine, Nutrition and Athletic Performance. Medicine & Science in Sports & Exercise, 48(3), 543–568.