Free online calculator · Health
Macronutrient Calculator
Estimate grams of protein, carbohydrate and fat from a daily calorie target and a selected macro split.
Formula • Worked example • Interpretation
Convert calorie targets to macronutrient grams
Macronutrients are carbohydrate, protein and fat. A macro calculator converts the calorie percentages you select into approximate grams per day.
Calculation method
Carbohydrate grams = calories × carbohydrate share / 4. Protein grams = calories × protein share / 4. Fat grams = calories × fat share / 9.
Worked example
At 2,000 kcal/day with 50% carbohydrate, 25% protein and 25% fat, the targets are 250 g carbohydrate, 125 g protein and about 55.6 g fat.
What your result means
Check that the shares add to 100%. A macro split may be one useful planning method, but food quality and overall intake also matter.
Tips for better calculations
Start with a realistic total calorie estimate; changing only the percentages does not change the chosen daily calorie total.
Assumptions and limitations
Energy conversion factors are approximations. Individual nutritional requirements differ, especially for children, pregnancy, or specific health conditions.
SiCalcs tools provide estimates and educational calculations; they do not replace professional financial, medical, tax, or legal advice.