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Carb-Loading Calculator

Calculate your daily carbohydrate target for pre-race carb loading based on bodyweight.

Result

Daily Carbohydrate Target
700 g
Approx. Calories from Carbs
2,800 cal

Carb loading protocols generally recommend this intake for 1-2 days before an endurance event lasting over 90 minutes, to maximize muscle glycogen stores - it's typically combined with reduced training volume (tapering) during the same window.

About the Carb-Loading Calculator

The Carb-Loading Calculator converts a bodyweight figure and a chosen grams-per-kilogram target into a daily carbohydrate intake goal, expressed in both grams and calories. It is built around the commonly cited endurance sports guideline of targeting roughly 8 to 12 grams of carbohydrate per kilogram of bodyweight per day in the 24 to 48 hours before a long event.

How It Works

Enter your bodyweight in kilograms and a target grams-per-kilogram figure (the default is 10 g/kg, within the commonly cited 8 to 12 g/kg range). The calculator multiplies the two to get a total daily carbohydrate target in grams, then multiplies that gram figure by 4, the standard calories-per-gram value for carbohydrate, to show the approximate calories that target represents.

Daily Carbohydrate Target (g) = Bodyweight (kg) x Target g/kg. Approx. Calories from Carbs = Daily Carbohydrate Target (g) x 4.

Formula & Methodology

For a bodyweight of 70 kg at a 10 g/kg target, multiply 70 by 10 to get 700 grams of carbohydrate for the day. Since each gram of carbohydrate provides roughly 4 calories, multiply 700 by 4 to get approximately 2,800 calories coming from carbohydrate sources across that day's meals and snacks.

Examples

A 70 kg Athlete At 10 g/kg

At the calculator's default inputs, 70 kg bodyweight and a 10 g/kg target, the daily carbohydrate goal is 70 x 10 = 700 grams, equal to about 2,800 calories from carbohydrate.

A Lighter Target At The Low End Of The Range

A 60 kg athlete choosing the lower end of the guideline range, 8 g/kg, gets a target of 60 x 8 = 480 grams of carbohydrate, or about 1,920 calories.

Advantages

  • Converts a general grams-per-kilogram guideline into a concrete daily number that is easier to plan meals and snacks around.
  • Shows the calorie equivalent of the gram target side by side, useful for cross-checking against a food diary or nutrition tracking app.
  • Lets you compare how the daily target shifts across the 8 to 12 g/kg guideline range before settling on a specific number.

Common Mistakes

  • Entering bodyweight in pounds instead of kilograms, since both the field and the underlying multiplication expect kg, which inflates the resulting target by roughly 2.2 times.
  • Treating the daily gram figure as a single meal or snack amount, when it is meant to be spread across multiple meals and snacks over one to two days.
  • Applying a carb-loading target to a race under about 90 minutes, a duration where glycogen depletion generally is not the limiting factor this style of guideline is meant to address.

Edge Cases to Watch For

  • There is no minimum-value check on bodyweight or grams-per-kg, so entering 0 for either field simply returns 0 grams and 0 calories rather than an error.
  • The 8 to 12 g/kg/day range referenced in the field's help text is a general sports nutrition guideline for continuous events lasting longer than about 90 minutes, not a figure tailored to any individual's body composition or specific event demands.
  • The calorie figure assumes a flat 4 calories per gram of carbohydrate and does not account for fiber content or the other macronutrients present in whatever foods are actually used to hit the gram target.

Common Use Cases

  • Endurance athletes such as marathoners, cyclists, and triathletes calculating a daily carbohydrate number for the day or two before a long event.
  • Coaches or nutrition-minded athletes translating a general g/kg guideline range into a specific gram and calorie figure for meal planning.
  • Anyone comparing how the low end versus the high end of the 8 to 12 g/kg range changes their daily carbohydrate total.
Written & fact-checked by the Calculateus TeamLast updated August 5, 2026How we verify our formulas

Frequently asked questions

Does carb loading work for shorter races too?

Research generally supports carb loading's benefit for continuous efforts lasting longer than about 90 minutes, where glycogen depletion becomes a limiting factor - for shorter races, normal daily carbohydrate intake is usually considered sufficient without a dedicated loading protocol.

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Conclusion

The Carb-Loading Calculator turns a bodyweight and a chosen grams-per-kilogram target into a specific daily carbohydrate goal in grams and calories. It reflects a commonly cited sports nutrition range for pre-endurance-event carb loading rather than an individualized dietary recommendation.