Ultra Fueling & Hydration Calculator
Enter your weight, expected time on feet, and conditions. You'll get per-hour carb, fluid, and sodium targets plus an aid-station plan — anchored on real endurance-nutrition research. Free, no signup.
Carbs / hour
g
Fluid / hour
oz
Sodium / hour
mg
Totals for the day
| Carbs | g |
| Calories (from carbs) | |
| Fluid | oz |
| Sodium | mg |
| Roughly equals | gels' worth of carbs |
Aid-station plan
Cumulative targets to check yourself against as the hours add up.
| Segment | Carbs | Fluid | Sodium | Cumulative carbs |
|---|
Cumulative carbs over time
Stay near this line — falling behind on carbs is what blows up ultras.
Email yourself this plan
We'll send the per-hour targets and totals so you can take them into your next long run.
A calculator can't see your training. Connect Strava and NavRun builds fueling and pacing around your real long runs, volume, and how your body responds — and updates as you train.
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Is this medical advice?
No. This is a research-anchored starting point, not medical or dietetic advice. Your gut and sweat are personal — test and dial in these numbers during long training runs, and talk to a professional if you have health concerns.
Where do these numbers come from?
Accepted endurance-nutrition ranges: roughly 60-90 g of carbs per hour (up to ~120 with a trained gut), about 16-27 oz of fluid per hour, and 300-800 mg of sodium per hour, scaled up for heat and heavier runners.
How accurate is it for my race?
It's a planning baseline, not a guarantee. Heat, vert, intensity, and how trained your gut is all move the real numbers. Practice your plan before race day, and connect Strava so NavRun can build fueling around your actual training.
Want this from your real training?
These tools run on what you type in. Connect Strava and NavRun builds your predictions, training paces, and race-day plans from your actual last-8-weeks of running.
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