Running Gel Calculator

Work out how many gels you’ll need for your race.













Choosing Your Carbs Per Hour Target

60 g/hour → A safe starting point for most runners. Easier on the stomach and often enough for half marathons or easier marathon pacing.

80 g/hour → A strong middle ground. Common choice for marathoners who have practiced gut training.

100 g/hour → Higher fueling strategy. Can work well if you’ve trained with this intake and tolerate it in long runs.

120 g/hour → Aggressive approach. Mostly used by elites or experienced ultra runners who have trained their gut extensively. Not for beginners to try on race day.

Tip: Gut training is as important as leg training. Always practice your chosen carb target in long runs well before race day.