Macro calculator: protein, carbohydrate and fat
Enter your daily energy and choose a split to see roughly how many grams of protein, carbohydrate and fat to aim for each day. If you don't know your energy needs yet, try the daily calorie goal calculator first.
What the result means
Food energy comes from three main groups: protein and carbohydrate provide about 4 kcal per gram and fat about 9 kcal per gram. This tool splits your energy by the chosen percentages and converts each part to grams.
The adult recommended ranges (AMDR) are protein 10–35%, carbohydrate 45–65% and fat 20–35% of energy. Every preset stays within them; a custom split outside them triggers a warning.
The grams are rough daily targets, not something to hit at every meal. Food quality, such as vegetables, whole grains and unsaturated fats, matters as much as the numbers.
How it is calculated
- Energy for each macronutrient = daily energy × share (%) ÷ 100
- Grams = that energy ÷ 4 (protein, carbohydrate) or ÷ 9 (fat), using the Atwater general factors (FAO), rounded to whole grams
- Kilojoules are converted first (1 kcal = 4.184 kJ)
- The three shares must total exactly 100%; otherwise nothing is calculated and you are asked to fix it
Limitations and cautions
- 4/4/9 are general averages; the real energy of each food varies slightly, and alcohol and fibre are not included
- AMDR ranges are for healthy adults. People with kidney disease, diabetes or other conditions that need nutrient control should use the split set by their doctor or dietitian
- Protein from a percentage split can differ from the daily protein tool (which is based on body weight); if they differ a lot, consider both
- This tool does not recommend foods or products
Results are estimates or basic screening only, not a medical diagnosis or medical advice.
Related articles
- Balanced nutrition: how much protein, carbohydrate and fat? ›
- 6 nutrients to pay attention to: what they do and where to find them ›
- Good fats, bad fats: how much you need and where to get them ›
- Protein 101: what it is, how much you need and the best sources ›
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References
- Food and Nutrition Board, Institute of Medicine: DRIs — Acceptable Macronutrient Distribution Ranges (adults: protein 10–35%, carbohydrate 45–65%, fat 20–35% of energy) (checked 16 Oct 2026) ↗ (opens in a new tab)
- FAO (2003): Food energy — methods of analysis and conversion factors, section 3.5.1 (Atwater general factors 4/4/9 kcal/g) (checked 16 Oct 2026) ↗ (opens in a new tab)
- NHLBI/NIH: The Practical Guide — Identification, Evaluation, and Treatment of Overweight and Obesity in Adults, pp. 13 and 29 (checked 16 Oct 2026) ↗ (opens in a new tab)
Compiled by Well Nutrition Hub from the sources listed. Content last reviewed 16 Oct 2026.