Macro Calculator

From TDEE to macros

Macronutrient targets start from total daily energy expenditure, or TDEE. This calculator first estimates your basal metabolic rate with the Mifflin-St Jeor equation: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + s, where s is +5 for men and −161 for women. Multiplying BMR by an activity factor (1.2 to 1.9) gives TDEE. Your goal then adjusts that number: cutting subtracts about 20%, maintaining keeps it, and bulking adds about 10%.

The resulting calorie target is divided into protein, carbohydrate and fat using the ratio you pick. Each gram of protein and carbohydrate supplies 4 calories, while each gram of fat supplies 9 calories. So for a given percentage split, protein grams are calories × P% ÷ 4, carb grams are calories × C% ÷ 4, and fat grams are calories × F% ÷ 9. Changing the preset instantly re-divides the same calorie budget.

Choosing a split

A balanced 30/40/30 split works well for general fitness. A high-protein 40/40/20 split supports strength training, muscle retention during a cut, and appetite control. Low-carb and keto splits shift energy toward fat and suit people who feel better with fewer carbohydrates, though they take some adjustment. Whatever you choose, protein is usually the macro worth prioritizing, especially while losing weight.

Practical notes and a disclaimer

These numbers are a starting framework, not a prescription. Track your weight and energy for two to three weeks and adjust calories up or down if progress stalls or feels too aggressive. Hydration, sleep, training and food quality all matter alongside macros. This page is for general information only and is not medical or nutritional advice; consult a registered dietitian for individual guidance. All calculations run locally in your browser and nothing is uploaded.

Worked example

Take a 30-year-old man who is 180 cm tall, weighs 80 kg and has a moderate activity level. BMR is 10 × 80 + 6.25 × 180 − 5 × 30 + 5 = 1,780 kcal, and TDEE is 1,780 × 1.55 = 2,759 kcal. The cut goal multiplies this by 0.8, giving about 2,207 kcal. With the balanced 30/40/30 split, protein is 2,207 × 0.30 ÷ 4 ≈ 166 g, carbohydrate is 2,207 × 0.40 ÷ 4 ≈ 221 g and fat is 2,207 × 0.30 ÷ 9 ≈ 74 g.

Gram values are rounded to whole numbers, so adding them back up can differ from the calorie target by a few calories. The split is chosen from four presets — balanced, high protein, low carb and keto — rather than typed freely, so if you want a different protein target, pick the closest preset and adjust portions manually.