Half Marathon Fueling Plan Calculator

Half marathon fueling plan calculator. Estimate gels needed, carbs/hour targets, and a simple schedule based on your finish time and preferences.

Fueling matters in the half marathon too. A small, consistent plan can keep effort steady and prevent late-race fade.

Gel estimate for 60-120 minutes
Carb targets and simple schedule
Adjusts for your finish time

How to plan half marathon fueling

Use your goal time to estimate gels needed and a simple fueling schedule for race day.

Select Half: Choose Half Marathon in the fuel planner.
Enter finish time: Use your goal time (or a recent race time).
Use the schedule: Follow the timing guidance and adjust based on what you practiced.

Frequently asked questions

Do I need gels for a half marathon?

It depends on duration and intensity. Many runners benefit from 1-2 gels, especially if racing hard for 90+ minutes.

Can I fuel with sports drink only?

Sometimes. If your drink provides enough carbs and you can carry it, you may not need many gels.

Fueling reference

Race-day carb targets and gel counts by finish time (baseline, no body weight entered)
Race	Finish time	Carbs/hour	Total carbs	Calories	Gels
Half marathon	1:20	45 g/hr	60 g	240 kcal	2
Half marathon	1:35	45 g/hr	71 g	284 kcal	3
Half marathon	1:50	45 g/hr	83 g	332 kcal	3
Half marathon	2:05	45 g/hr	94 g	376 kcal	4
Half marathon	2:20	45 g/hr	105 g	420 kcal	4
Marathon	2:50	75 g/hr	213 g	852 kcal	5
Marathon	3:15	75 g/hr	244 g	976 kcal	5
Marathon	3:45	75 g/hr	281 g	1124 kcal	6
Marathon	4:15	75 g/hr	319 g	1276 kcal	7
Marathon	4:45	75 g/hr	356 g	1424 kcal	7
Marathon	5:15	75 g/hr	394 g	1576 kcal	7

Method and sources

The numbers on this page are computed with the same code as the TrainPace calculators, from these published methods. They are training guidance, not medical advice.

Jeukendrup, A. (2014). A step towards personalized sports nutrition: carbohydrate intake during exercise. Sports Medicine 44(Suppl 1), S25–S33 — carbohydrate targets by event duration, and glucose + fructose for intakes above 60 g/hr.
Thomas, D.T., Erdman, K.A. & Burke, L.M. (2016). Nutrition and Athletic Performance (joint position statement of the ACSM, Academy of Nutrition and Dietetics, and Dietitians of Canada). Medicine & Science in Sports & Exercise 48(3), 543–568.

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