How macros work
The three macronutrients each supply a fixed number of calories per gram: protein 4 kcal/g, carbohydrate 4 kcal/g, and fat 9 kcal/g. This calculator takes your daily calorie budget, applies your chosen percentage split, and converts each share into grams you can actually track with a food app or scale.
Choosing a split
| Style | Split (P/C/F) | Typically suits |
|---|---|---|
| Balanced | 30 / 40 / 30 | General health, most training styles |
| High protein | 40 / 30 / 30 | Fat loss phases, preserving muscle |
| Low carb | 35 / 25 / 40 | Lower appetite on fewer carbs |
| Keto | 30 / 5 / 65 | Strict very-low-carb approaches |
Research consistently shows that total calories drive weight change and adequate protein protects muscle; the remaining carb-to-fat balance is mostly personal preference and adherence. Pick the style you can sustain, not the one that sounds most impressive.
A protein rule of thumb
Active adults generally do well with roughly 1.6–2.2 g of protein per kg of body weight per day. If the percentage split gives you a protein number far below that range for your weight, consider the high-protein preset instead.
Related tools
Start with your TDEE to find your daily burn, set a target with the calorie calculator, then come back here to split it into macros.
Sources & references
- Institute of Medicine. Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Protein and Amino Acids. 2005.
- Morton RW, et al. A systematic review of protein supplementation on resistance training–induced gains. Br J Sports Med. 2018;52:376–384.