How the macro calculator works
In percent mode, the calculator converts each macro share into calories, then grams. Carbohydrate and protein use 4 kcal/g; fat uses 9 kcal/g. In protein-first mode, protein is calculated from body weight and the remaining calories are split between carbohydrate and fat by the percentages you enter.
Example
At 2,200 kcal with a 45% carbohydrate, 25% protein and 30% fat split, the daily targets are about 248 g carbohydrate, 138 g protein and 73 g fat. Dividing by 4 meals gives a practical per-meal average.
Common mistakes
Make sure the percentages add to 100% in percent mode. In protein-first mode, check that the remaining calorie split still leaves enough fat and carbohydrate for a realistic diet.
How to use the macro targets
A useful macro target is more than three numbers. Check that the percentages make sense, compare the per-meal averages, and remember that food quality, medical context and adherence matter more than a mathematically neat split.
Assumptions and limitations
- This is a planning calculator, not medical nutrition advice.
- Macro targets should be interpreted with total calories, food quality, fibre, micronutrients, training and health status.
- Clinical diets and sensitive health situations require qualified professional guidance.
References
- FAO: Food energy conversion factors - energy conversion context for macronutrients, accessed 2026-05-17.
- WHO: Healthy diet fact sheet - healthy diet context and fat/carbohydrate guidance, accessed 2026-05-17.
FAQ
Do the macro percentages need to add up to 100%?
Yes. If you use percentage mode, carbohydrate, protein and fat should add to 100% of daily calories.
Why does fat use 9 kcal per gram?
General food-energy conversion factors commonly use 9 kcal/g for fat and 4 kcal/g for carbohydrate and protein.
Is this medical nutrition advice?
No. It is a planning calculator. Clinical diets, eating disorders, pregnancy, diabetes, kidney disease and other medical situations need qualified care.
Last reviewed: 2026-05-17