Plan fuel for your run
Fuel range
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Enter carbohydrate per serving to estimate how many servings to carry.
The target changes with duration. Practice any race-day plan in training and adjust for intensity, conditions, access to aid stations, and gut comfort.
How the fuel target is chosen
The calculator follows the Australian Institute of Sport carbohydrate guidance for exercise duration. The ranges describe carbohydrate consumed during the run, not your full-day nutrition needs:
| Run duration | Planning target |
|---|---|
| Up to 45 minutes | On-run carbohydrate usually not needed |
| 45–75 minutes | Small amounts may help during sustained high-intensity work |
| More than 75 minutes–2.5 hours | 30–60 g per hour |
| More than 2.5 hours | 60–90 g per hour when practiced and tolerated |
For the 45–75 minute band, the calculator shows up to 30 g as a practical small amount—the upper end of the 20–30 g typically supplied by one sports gel. This is a planning aid, not an intake requirement.
Worked example: a two-hour long run
A two-hour run falls in the 30–60 g/hour band, producing a total target of 60–120 g. If each gel contains 25 g, that is 2.4–4.8 gel equivalents. Carrying five covers the upper end, while one serving every 25–50 minutes spans the target range.
Turn the number into a workable plan
- Start with the lower end if you are new to fueling while running, then build gradually in training.
- For intakes above 60 g/hour, products using multiple transportable carbohydrates such as glucose and fructose may improve absorption and tolerance.
- Sports gels are concentrated; take them with water unless their label says otherwise.
- Count carbohydrate from every source, including drink mix, gels, chews, bars, and food.
- Do not try a new product or a high intake for the first time on race day.
Fuel is only one part of the plan
This calculator does not prescribe fluid, sodium, caffeine, pre-run meals, or recovery nutrition. Hydration needs vary substantially with sweat rate, climate, pace, body size, and access to drinks. Avoid forcing fluid beyond thirst or a practiced individual plan.
Sources and review
The duration bands and carbohydrate targets come from the Australian Institute of Sport sports bar guidance and sports gel guidance. The AIS also recommends practicing a fueling strategy to account for individual goals and gut comfort. Health-adjacent content follows the RunCalcs editorial source-check policy.
Reviewed by the RunCalcs Editorial Team: 8 August 2026.
This calculator provides general sports-nutrition education. Athletes with diabetes, gastrointestinal conditions, eating disorders, allergies, pregnancy, or other medical needs should seek an individual plan from an accredited sports dietitian or appropriate clinician.
Run fuel calculator FAQs
Do I need a gel for every run?
No. On-run carbohydrate is generally unnecessary for sessions under 45 minutes. Longer or harder runs are where an intentional fueling plan becomes more useful.
Why does the calculator give a range?
Duration guidelines are deliberately broad. The right point within the range depends on pace, goals, what you ate beforehand, product tolerance, and how well you have practiced taking carbohydrate while running.
Does one serving always mean one gel?
No. Enter the carbohydrate grams in the portion you intend to consume. A serving can be a gel, chew pack, bar, food portion, or measured quantity of sports drink.
Should I aim for 90 g/hour on every long run?
No. Ninety grams per hour is the upper end for prolonged endurance exercise and normally requires practice. Start lower and increase only when the duration, intensity, performance goal, and gut tolerance justify it.