Carbohydrate Calculator

1. Enter your daily calorie goal. Use a TDEE calculator to find your maintenance calories, then adjust for your goal (subtract 300-500 for fat loss, add 200-300 for muscle gain).
2. Choose a diet type. The preset buttons fill in typical macro splits for that eating style. You can fine-tune the percentages manually after selecting a preset.
3. Adjust percentages to total 100%. Carbs, protein, and fat must add up to exactly 100%. The status indicator turns green when balanced.
4. Read your daily gram targets. The results show grams per day for each macro and how many calories each macro contributes.
5. Use the food reference table. Cross-reference common foods to see how easily you can hit your carb target with real meals.

Each macronutrient provides a fixed number of calories per gram. The calculator uses these values to convert calorie targets into gram targets:

Carbohydrates: 4 calories per gram
Protein:       4 calories per gram
Fat:           9 calories per gram

Formula:

Carb calories  = Total calories × (Carb % / 100)
Carb grams     = Carb calories / 4

Protein grams  = (Total calories × Protein %) / 4
Fat grams      = (Total calories × Fat %) / 9

Worked example at 2,000 calories with a moderate split (50% carb, 25% protein, 25% fat):

Carbs:   2000 × 0.50 = 1000 kcal / 4 = 250g
Protein: 2000 × 0.25 = 500 kcal  / 4 = 125g
Fat:     2000 × 0.25 = 500 kcal  / 9 = 56g

The DRI (Dietary Reference Intake) recommends that carbohydrates provide 45 to 65% of total calories for healthy adults. The minimum is 130g/day to meet brain glucose needs without entering ketosis.