Ascend Carb Loading Calculator
Ascend tools

Carb Loading Calculator

Estimate daily carbohydrate targets for race week based on body weight, event type, and loading duration.

Inputs

For most endurance races, a 24-48 hour carb load is practical. Longer events may benefit from 2-3 days depending on training status, gut tolerance, and total calorie needs.

Daily target

Recommended carb range

Lower target
610g
10 g/kg body weight
Upper target
732g
12 g/kg body weight
Total carbs
1220-1464g
Across the full load
Carb calories
2440-2928
Calories from carbs per day
Meal target
153-183g
Per meal across 4 meals

Reference ranges

Moderate load
Long runs, half marathons, lower-volume race prep
7-9 g/kg
Standard endurance load
Marathon, HYROX, hard race day efforts
10-12 g/kg
Extended load
Ultra, Ironman, very long duration events
11-13 g/kg

Use lower-fiber, familiar carbohydrate sources as race day gets closer. Keep protein moderate, reduce very high fat intake, and avoid testing new foods during race week.