Macro Calculator

Macronutrients are the three nutrients your body needs in large amounts: protein, carbohydrates, and fat. Protein and carbs provide 4 kcal per gram, while fat provides 9 kcal per gram. Together they make up all of your daily calories, and the ratio between them — your macro split — influences body composition, energy, and performance. Our macro calculator works out the exact grams of each for your calorie target.

Sports-nutrition consensus puts protein at about 1.6 g per kg of body weight for most active people, rising to 2.0–2.4 g/kg when you are in a calorie deficit to preserve lean mass, and 1.4–1.8 g/kg for muscle gain. A 70 kg person would aim for roughly 112–140 g of protein per day. Our calculator lets you set protein either as a percentage of calories or directly in g/kg.

For lean muscle gain, set protein at about 1.6–2.2 g per kg of body weight, keep fat moderate at 20–30% of calories for hormone health, and let carbohydrates fill the remaining calories of your 250–500 kcal surplus. A balanced split like 30% protein / 40% carbs / 30% fat is a common starting point, with carbs fueling training performance.

When cutting, raise protein to 2.0–2.4 g per kg of body weight to protect muscle and increase satiety, keep fat at or above roughly 20% of calories (and above ~0.5 g/kg) for hormonal health, and reduce carbs to fill the rest of your deficit. High-protein and low-carb presets in our calculator match this approach automatically.

Protein and carbohydrates each provide 4 calories per gram, while fat provides 9 calories per gram — more than double. Alcohol provides 7 kcal per gram but is not a macronutrient. This is why a keto diet with high fat can be calorie-dense, and why tracking grams (not just calories) matters for hitting a macro split.

A ketogenic split (roughly 70% fat, 25% protein, 5% carbs — under 20–50 g of carbs per day) is an effective therapeutic diet for some people, but it sits far outside general-health ranges and can be hard to sustain. The IOM AMDR for carbs is 45–65% of calories. Our calculator flags keto and other extreme splits with guidance notes so you can make an informed choice.

The Institute of Medicine's Acceptable Macronutrient Distribution Ranges for general health are: protein 10–35% of calories, fat 20–35%, and carbohydrates 45–65%. Staying within these ranges helps ensure adequate micronutrient intake and lower chronic-disease risk. Performance, low-carb, and ketogenic diets intentionally fall outside them — which is fine for short periods, but worth planning carefully.

Yes. The calculator is 100% free with no registration, and every calculation runs entirely in your browser — no data is ever sent to a server. If you choose to save results, they are stored only in your browser's localStorage, and you can export, import, or clear your history at any time.