Carbohydrate Intake & g/kg Calculator

How to calculate carbohydrate requirements?

Carbohydrate needs are not static; they scale directly with your body mass. This scaling ensures that your muscle glycogen stores are adequately supported relative to the volume of tissue being utilized during physical exertion.

Formula: Total Carbs (g) = Weight (kg) × g/kg Ratio

Using the Carbohydrate Calculator: an example

Example: An athlete weighing 75kg aiming for a high-intensity intake of 8g/kg to prepare for a heavy training day.

Step-by-step calculation:

1. Identify weight: The athlete weighs 75kg.
2. Choose target ratio: Based on intensity, a ratio of 8g/kg is selected.
3. Multiply values: 75kg × 8g/kg = 600g of carbohydrates total.

Frequently Asked Questions

Why use g/kg instead of percentages?

The g/kg method ensures you get enough fuel for your specific muscle mass. Percentages can be misleading if your total calorie intake is too high or too low for your needs.

What is a low-intensity dose?

A low-intensity dose is typically 3–5g of carbohydrates per kilogram of body weight, intended for light training or skill-based activity days.

When should I use the 10-12g/kg range?

This range is used for carbohydrate loading 36–48 hours before an extreme endurance event (like an Ironman or marathon) or during ultra-high-volume training weeks.

Does fiber count toward these totals?

Most performance guidelines focus on total carbohydrates listed on nutrition labels. However, for precise fueling, some athletes prioritize "net" carbs (total carbs minus fiber).