How Many Gels for a Half Marathon?

Estimate how many gels you need for a half marathon. Use your finish time to get a carb target and a simple gel schedule.

Most runners don't need a large gel load for a half, but 1-2 well-timed gels can make the last 5K feel much better.

Gel estimate for your goal time
Timing guidance
Works with drink + gel combos

How to estimate half marathon gel count

Use your goal time and intensity to decide whether you need gels and how many.

Enter goal time: Input your half marathon goal time.
Pick fueling approach: Decide gels-only or gels + sports drink.
Set timing: Use a steady schedule you practiced in training.

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

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