Macro Calculator
Free macro calculator. Split a daily calorie target into protein, fat, and carb grams for balanced, low-carb, high-protein, or keto diets.
What a macro split is
Macronutrients — protein, fat, and carbohydrate — are the three nutrients that supply your calories. A macro split turns a daily calorie target into grams of each, so you know what to actually eat rather than just how much. This calculator converts a calorie target into grams using one of four preset ratios, and shows both the grams and the calories each macro contributes.
How the macro calculator works
- Protein and carbohydrate supply 4 calories per gram; fat supplies 9 calories per gram.
- Each preset sets the share of total calories that comes from each macro; grams are then calculated from those shares and rounded to whole numbers.
- Because of that rounding, the grams shown can add up a few calories either side of the target. The drift is normally 1–3% and does not matter in practice.
- The donut and table display grams, calories, and percentage for each macro at the same time.
A worked example
A 2,200 kcal target on the balanced preset (30% protein, 30% fat, 40% carbohydrate):
| Macro | Share | Calories | Grams |
|---|---|---|---|
| Protein | 30% | 660 | 165 g |
| Fat | 30% | 660 | 73 g |
| Carbohydrate | 40% | 880 | 220 g |
The grams round to whole numbers, so 165 g protein + 73 g fat + 220 g carbohydrate recalculate to about 2,197 kcal — a three-calorie difference that has no practical effect.
The four presets
| Preset | Protein | Fat | Carbs | Typical use |
|---|---|---|---|---|
| Balanced | 30% | 30% | 40% | General eating |
| Low-carb | 35% | 45% | 20% | Appetite control, fewer carbs |
| High-protein | 40% | 30% | 30% | Holding muscle in a deficit |
| Keto | 25% | 70% | 5% | Very low carb, ketogenic |
How to choose a split
Total calories drive weight change; the split mostly affects what you can sustain and how training feels. Protein is the macro worth being deliberate about — roughly 1.6 g per kilogram of bodyweight covers most goals, and higher intakes help protect muscle in a deficit. Keep fat high enough for satiety and normal hormone function, and let carbohydrate fill the remainder, with more if you train hard. Whichever preset you pick, the ratio is a starting point to adjust, not a rule to obey.
Common mistakes
- Chasing a perfect ratio. Hitting calories and protein consistently matters far more than matching a split to the gram.
- Too little protein. A low-protein deficit costs muscle. Anchor protein first, then divide the rest.
- Assuming keto is magic. The preset is only a ratio; fat loss still comes down to the calorie deficit.
- Forgetting fibre. Very low-carb splits can shortchange fibre and micronutrients. Build in vegetables whatever the ratio.
Frequently asked questions
Do macros matter more than calories?
Calories decide weight; macros shape body composition and how you feel on the way. You cannot out-split a surplus, and you cannot hold muscle through a deficit without enough protein. Get calories roughly right first, then refine the split.
How much protein do I need?
A common evidence-based range is 1.6–2.2 g per kilogram of bodyweight for people training to build or retain muscle. The high-protein preset pushes toward the top of that range.
Can I use my own percentages?
Not directly here — the calculator offers four fixed presets. To build a custom ratio, convert your own percentages into grams (4 kcal/g for protein and carbohydrate, 9 kcal/g for fat). A percentage calculator makes the shares quick to convert.
Where does the calorie target come from?
You supply it, and it should come from your maintenance level adjusted for your goal. Use the TDEE calculator to estimate maintenance, then subtract 300–500 kcal to lose or add roughly 300 to gain.
Once your grams are set, the fastest way to keep them honest is to log a few typical days and see where you actually land. If training or energy suffers, adjust the split rather than the calorie target.