The small print, in plain language
Disclaimer
Nothing on this site is medical advice. The calculator, the prompt generator and the guides produce training-tested starting points based on general sports-science ranges. They know nothing about your health, medications, or history. You are responsible for testing anything you try — in training, gradually, never for the first time on race day.
Talk to a professional first if any of these apply
Diabetes or glucose-control conditions
Everything on this site is concentrated carbohydrate. Fuelling strategies interact directly with blood glucose management — plan with your clinician, not a calculator.
Kidney disease, high blood pressure, or a sodium-restricted diet
The sodium ranges here (400–900 mg/h) assume healthy kidneys and normal blood pressure. Do not add sodium to your fuelling against medical advice.
Caffeine sensitivity or heart-rhythm conditions
The 3–6 mg/kg caffeine guidance is a general sports-science range, not a personal prescription. Caffeine raises heart rate and can trigger arrhythmias in susceptible people.
History of GI distress
Concentrated carbohydrate is a common trigger. Start well below the default targets and increase only as tolerated.
Heat-illness risk
Hot and humid conditions change fluid, sodium and carbohydrate needs substantially. When in doubt, prioritise fluids and cooling over hitting a carb number.
Allergies and intolerances
Check every ingredient — commercial gels and DIY ingredients alike. Fructose malabsorption in particular makes standard glucose:fructose ratios a bad fit.
About caffeine
Caffeine is deliberately excluded from the calculator's recipes. The general guidance (3–6 mg per kg of bodyweight, 30–60 minutes before, tested in training) appears as a note only. Never handle pure caffeine powder — the difference between a dose and a dangerous dose is smaller than kitchen scales can measure. Use commercial products with a stated, measured dose.
About the numbers
The gut-load indicator is an estimate derived from carbohydrate concentration, ingredient type and sodium — not a laboratory osmolality measurement, which cannot be computed reliably from consumer ingredients. Commercial product prices are typical single-unit prices at the date shown and will drift; sodium and caffeine vary by flavour. Costs from the calculator are estimates built from the ingredient prices you enter.
Questions about how something is calculated? The methodology is described alongside each tool, and theAbout page explains the site's approach.