Macros Calculator

Macros are the three nutrients that provide calories — protein, fat and carbohydrates. Counting them instead of just calories helps you hit body-composition goals (lose fat, build muscle) more precisely, because where your calories come from matters almost as much as how many there are.

Why macros beat plain calories

Two people can eat the same number of calories with very different results. A bodybuilder and an office worker on identical daily totals would not build the same physique, largely because of protein: at an equal calorie intake, the person getting enough protein holds onto muscle during a cut and supports new muscle during a bulk. Fat matters too — it carries fat-soluble vitamins and supports hormone production, while carbohydrates are the body's preferred fuel for training. Tracking macros simply makes sure none of the three is starved.

Step 1 — calorie target

Your TDEE comes from BMR × activity. Then adjust for the goal:

Cut:      TDEE − 500
Maintain: TDEE
Bulk:     TDEE + 500

Step 2 — protein (by body weight)

Protein protects muscle when cutting and builds it when bulking:

Protein and carbs supply 4 kcal per gram; fat supplies 9 kcal per gram. These 4-9-4 values trace back to the 19th-century work of Wilbur Atwater and are baked into food labels everywhere — they are the link between the grams you eat and the calories they provide.

Step 3 — fat and carbs

Fat gets about 25% of calories (divide by 9 for grams). The remaining calories go to carbs (divide by 4).

Example

A 30-year-old man, 175 cm, 75 kg, moderately active, maintaining, moderate protein:

• TDEE ≈ 2,633 kcal → target 2,633 kcal
• Protein = 75 × 1.6 = 120 g → 480 kcal
• Fat = 2,633 × 0.25 ÷ 9 ≈ 73 g → 658 kcal
• Carbs = (2,633 − 480 − 658) ÷ 4 ≈ 374 g

Making it practical

Gram targets can feel abstract until you picture them on a plate. Roughly, 100 g of cooked chicken breast is about 30 g of protein, a serving of rice roughly 40 g of carbohydrate, and a tablespoon of olive oil about 14 g of fat. Once you have your numbers, weighing food for a week or two teaches you what a "120 g" day actually looks like, after which most people can estimate by eye. If hitting protein feels like a struggle, that is normal — it is often the hardest macro to reach, which is why protein-rich snacks and shakes exist.

These splits are starting points. Adjust after 2–3 weeks based on how your weight and energy respond. This content is general education, not dietary or medical advice.