Carb Loading Calculator — Pre-Race Carbohydrate Plan

Marathon or big event coming up? Enter your body weight to get science-based carbohydrate targets for the 3 days before race day.

🍝 Carb Loading Plan

How the carb loading calculator works

Carb loading maximizes muscle glycogen stores before endurance events lasting 90+ minutes. Sports nutrition guidelines recommend 8–12 g of carbohydrate per kg of body weight per day for 1–3 days before the event, combined with tapered training.

Stick to familiar, low-fiber foods during loading — race week is not the time to experiment with new meals.

Why use our carb loading calculator?

LaCalc’s carb loading calculator is free, fast, and private. No sign-up, no downloads — type your numbers and get instant results. Every calculation runs in your browser, so your data never leaves your device.

Frequently asked questions

How many days should I carb load?
1–3 days is enough for most runners. Longer loading offers little extra benefit and can cause bloating.
Will carb loading make me gain weight?
You may gain 1–2 kg — that is water stored with glycogen, and it is exactly what powers you on race day.
What foods are best for carb loading?
Rice, pasta, oats, bread, potatoes, and bananas. Keep fat and fiber moderate to avoid stomach issues.