Macro calculator
Enter your profile and your goal. The calculator estimates your daily calories with the Mifflin-St Jeor equation, then turns them into grams of protein, carbohydrate and fat under four common splits, shown side by side.
About 30 seconds
How the estimate is built
Resting metabolic rate (Mifflin-St Jeor) = 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5 for men, − 161 for women.
Total daily expenditure = resting metabolic rate × activity factor, from 1.2 (sedentary) to 1.9 (extremely active). This is exactly what the site's TDEE calculator does, so the two tools return the same number for the same profile.
Goal: − 20 % to cut, total expenditure to maintain, + 10 % to gain. The deficit is never allowed below the resting metabolic rate, which acts as a floor.
Splits: protein is set in grams per kilo of body weight (1.6 to 2.2 g/kg depending on the split), fat as a share of calories (25 to 55 %), and carbohydrate takes what is left. A pure percentage split looks tidier but breaks at the extremes: 30 % protein on a 3,000 kcal day is 3 g/kg, far above anything published.
For a profile of 75 kg and 178 cm, aged 30, with an activity factor of 1.550, the Mifflin-St Jeor equation gives a resting metabolic rate of 1,718 kcal and a total daily expenditure of about 2,662 kcal. The selected goal works out at 2,662 kcal a day, or 135 g of protein, 331 g of carbohydrate and 89 g of fat in the balanced split.
Sources: Mifflin MD, St Jeor ST et al., A new predictive equation for resting energy expenditure in healthy individuals (Am J Clin Nutr, 1990); ISSN Position Stand: Protein and Exercise, Jäger et al. (J Int Soc Sports Nutr, 2017) for the 1.4 to 2.0 g/kg protein band; ACSM / Academy of Nutrition and Dietetics / Dietitians of Canada, Nutrition and Athletic Performance (Med Sci Sports Exerc, 2016) for the 5 to 7 g/kg carbohydrate figures.
This is an estimate, not a meal plan and not medical advice. A prediction equation gets resting expenditure right to within about 10 %, and two people with the same profile can differ by several hundred kilocalories. Treat these numbers as a starting point, adjust them over two to three weeks of weight and measurements, and speak to a doctor or a registered dietitian for anything clinical — pregnancy, a diagnosed condition, a history of disordered eating.
Your calories, line by line
| Line | Calories |
|---|---|
| Resting metabolic rate (Mifflin-St Jeor) | 1,718 kcal |
| Total daily energy expenditure (× activity factor) | 2,662 kcal |
| Cut (− 20 %, floored at the resting metabolic rate) | 2,130 kcal |
| Maintain | 2,662 kcal |
| Bulk (+ 10 %) | 2,928 kcal |
Four splits at 2,662 kcal
| Split | Protein | Carbs | Fat |
|---|---|---|---|
| Balanced 20 / 50 / 30 % | 135 g | 331 g | 89 g |
| High protein 25 / 50 / 25 % | 165 g | 334 g | 74 g |
| Low carb 23 / 22 / 55 % | 150 g | 149 g | 163 g |
| Endurance 18 / 57 / 25 % | 120 g | 379 g | 74 g |
How to use these numbers
Start with protein: it is the line that moves the least and matters the most for holding on to muscle, whether you are cutting or gaining.
The 135 g of protein in the balanced split is a daily total, not a per-meal one: spread it over three to five servings.
Then adjust on the evidence: if your weight has not moved the way you want after two to three weeks at a steady intake, change the calories by 5 to 10 %, not the protein.
Calories matter more than the exact split: moving from 40 % to 45 % carbohydrate changes almost nothing as long as the daily total and the protein hold.
Fine-tune my protein intake · See all calculators
Frequently asked questions
Here are some common questions about the macro calculator.
In three steps. Estimate the resting metabolic rate with Mifflin-St Jeor, multiply it by an activity factor between 1.2 and 1.9 to get total daily expenditure, then adjust for the goal: − 20 % to cut, + 10 % to gain. The resulting calories are split into protein (1.6 to 2.2 g per kilo of body weight), fat (25 to 55 % of calories) and carbohydrate, which takes the remainder.
The one that keeps the deficit liveable and protein high. In practice that means 1.8 to 2.2 g of protein per kilo, enough fat to stay above roughly 20 % of calories, and carbohydrate set by your training and your appetite. Trials comparing different splits at matched calories and protein find no clear winner.
The ISSN puts protein for exercising individuals at 1.4 to 2.0 g per kilo per day. The ACSM recommends 5 to 7 g of carbohydrate per kilo for moderate daily training, and up to 10 g/kg for heavy endurance work. Fat should not sit below about 20 % of calories for long. The rest is preference.
Not forever. Weighing for two or three weeks teaches you what a portion looks like and exposes the gaps — cooking oil, nuts, drinks. After that, tracking protein loosely and weighing yourself once a week is enough for most people. This calculator gives an estimate, not a meal plan.
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