How to use
- Enter the inputs.
- Sanity-check the outputs.
- Use the result as a planning anchor, not a promise.
Jump to
Tool
Inputs → outputs
This page is intentionally practical: get numbers first, then read the how-to.
Inputs
- • Finish time (hh:mm)
- • Carbs per hour (g/h)
- • Dose interval (minutes)
- • Carbs per gel (g) (optional)
Outputs
- • Total carbs (g)
- • Approx gels (count)
- • Dose schedule
Export
Print or share the tool
Useful outputs beat generic SEO copy. Print a PDF or share this page before race week.
Tip: print or save as PDF for race week.
Example presets
Prefill with a realistic scenario
Pick an example to prefill the calculator, then tweak inputs for your own training week.
Loading fueling planner…
Quick answers
The 60-second version
Snippet-ready answers to common questions. Use the calculator above for the numbers.
What carb target should I use?
Use a target you can tolerate in training. Many athletes land somewhere between 60–90 g/h, but the right number is individual.
When should I start taking carbs?
Earlier than you think. A simple rule is start within the first 30 minutes, then follow the schedule.
Do I need sodium?
It depends on sweat rate, heat, and what you tolerate. If you use electrolytes, practice with them in training and avoid overdoing it.
Assumptions
What this tool assumes
- • Carb target is a training-tested number for you (GI tolerance varies).
- • You can execute the schedule while running (practice with the same products).
Limitations
What can break it
- • Does not prescribe medical nutrition or account for diabetes or GI disease.
- • Heat, intensity, and aid-station options change what’s practical; adjust on race week.
Related
Use this with a plan
Coaching beta
Get a plan that adapts to your life.
Join the 26weeks.ai TestFlight beta for adaptive coaching, recovery-aware adjustments, and race-week reminders.
FAQs
What carb target should I use?
Use a target you can tolerate in training. Many athletes land somewhere between 60–90 g/h, but the right number is individual.
When should I start taking carbs?
Earlier than you think. A simple rule is start within the first 30 minutes, then follow the schedule.
Do I need sodium?
It depends on sweat rate, heat, and what you tolerate. If you use electrolytes, practice with them in training and avoid overdoing it.
Keep going
18-Week Marathon Training Plan
A 18-week marathon training plan with week-by-week structure, workouts, adaptation rules, and built-in pace + fueling tools. Variations are included on one page.
24-Week Marathon Training Plan
A 24-week marathon training plan with week-by-week structure, workouts, adaptation rules, and built-in pace + fueling tools. Variations are included on one page.
Marathon Races (Directory + Athlete Guides)
Curated marathon race directory with athlete guides. Facts include sources, verification timestamps, and planning tools.
BMW Berlin Marathon 2026: date, registration, course, weather
Athlete guide for BMW Berlin Marathon 2026: date, location, climate context, training timeline, and pacing/fueling tools.
Taper Week Checklist (Arrive Fresh, Not Flat)
A practical taper checklist: what to reduce, what to keep, and what to rehearse so race week is calm and repeatable.