Race fueling
Race plan calculator
Start with a generic half marathon, marathon, or ultra, then connect a course if you want your plan aligned to aid stations.
How to build your race plan
- 1Pick a generic half marathon, marathon, or ultra, or connect a mapped course to align the plan to real aid stations.
- 2Enter your target finish time or pace so fuel can be scheduled by the clock rather than by distance.
- 3Set your body weight, sweat profile, and expected weather, which together drive fluid and sodium targets.
- 4Choose the gel, drink mix, or chew you actually train with so the carb maths matches the products in your pockets.
- 5Review the timed plan, then rehearse it in a long run before race day rather than trying it for the first time on the start line.
What the numbers are based on
- Carbohydrate targets follow the widely used 30 to 60 g per hour range for endurance racing, with higher intakes only for athletes who have trained their gut to tolerate them.
- Fluid needs vary enormously between runners, so a sweat-rate estimate beats any fixed millilitres-per-hour rule.
- Sodium matters most in long, hot races and for athletes who finish sessions with visible salt on their skin and kit.
- Caffeine is planned as a total race dose rather than per gel, because it is easy to stack far more than you rehearsed.
- A plan you can execute while tired beats a theoretically optimal plan you abandon at halfway.
Race plan calculator FAQ
What does the race plan calculator do?
It turns your race distance, target finish time, body metrics, weather, and chosen fuel products into a timed race-day plan: how many carbs per hour to take, when to take each gel or drink, and roughly how much fluid and sodium to aim for.
Is the race plan calculator free?
Yes. The calculator is free to use and needs no account. The Mavr app adds training-aware daily nutrition around the race and lets you save fuel kits and rehearse the plan in training.
Can I build a plan for a specific race course?
Yes. Connecting a mapped course aligns the plan to that race's real aid stations, so your fuel and fluid timings land where drinks are actually available instead of at arbitrary intervals.
How many carbs per hour should my race plan use?
Most endurance runners land between 30 and 60 g of carbohydrate per hour. Trained athletes racing longer than about two and a half hours can work toward 90 g per hour, but only after practising that intake repeatedly in training.
Should I use this plan without practising it?
No. Rehearse the plan in at least one or two long runs at similar intensity and, ideally, similar weather. Race day is the worst possible time to discover that a product or a carb target does not sit well.