Carbohydrate Loading Calculator
Carbohydrate loading is one of the most evidence-based nutritional strategies for improving endurance performance. By increasing muscle glycogen stores above their resting level in the days before a long event, athletes can delay the onset of fatigue (glycogen depletion) and sustain a higher race pace. This calculator computes your target carbohydrate intake per day during the loading phase based on body weight and chosen loading intensity. It also breaks down the carbohydrate content into approximate equivalent servings of common high-carbohydrate foods to make meal planning practical.
Carbohydrate loading formula
Daily carb target (g) = Body weight (kg) x Carb factor (g/kg/day)
Calories from carbs = Daily carb target x 4 kcal/g
White rice: approx 45g carbs per cooked cup
Pasta: approx 43g carbs per cooked cup
Source: Burke LM et al. (2011). Carbohydrates for training and competition. Journal of Sports Sciences, 29(S1), S17-S27.
Frequently asked questions
What is carbohydrate loading?
Carbohydrate loading (glycogen supercompensation) is a nutritional strategy used before endurance events lasting more than 90 minutes. By consuming a high-carbohydrate diet 1 to 3 days before a race, athletes can increase muscle glycogen stores above normal, delaying fatigue.
How many grams of carbohydrate per kg should I eat during loading?
Sports dietitian guidelines recommend 10 to 12 g of carbohydrates per kg body weight per day for the 1 to 3 days before an event. This is approximately 700 to 840 g/day for a 70 kg athlete - significantly more than a typical diet.
Does carbohydrate loading work for all endurance events?
Carbohydrate loading is most beneficial for events lasting 90 minutes or longer at moderate-to-high intensity, such as marathons, triathlons, cycling road races, and cross-country skiing. For events under 90 minutes, glycogen stores are typically adequate without deliberate loading.
What foods are best for carbohydrate loading?
High-carbohydrate, low-fibre foods are preferred to maximise glycogen storage while minimising GI distress: white rice, white pasta, bread, potatoes, bananas, sports drinks, energy gels, and low-fat cereals. Avoid high-fat, high-fibre foods that slow digestion and may cause discomfort.
Does carbohydrate loading cause weight gain?
Yes, temporarily. Each gram of glycogen is stored with approximately 3 g of water. Carbohydrate loading can increase body weight by 1 to 3 kg. This water and glycogen are rapidly used during the event and should not be confused with fat gain.
Official sources
- Academy of Nutrition and Dietetics / ACSM / Dietitians of Canada: Joint Position Statement on Nutrition and Athletic Performance.
- USDA FoodData Central: USDA Nutrient Database (carb content of foods).
Reviewed by the CalculatorHub team, edited by James Graham, 14 June 2026. See our methodology.