How to Calculate Your Macros
Macronutrients — protein, carbohydrates and fat — are the three main categories of nutrients that provide calories. Calculating your macros starts with your TDEE (Total Daily Energy Expenditure), then allocating those calories based on your goal.
Step 1 — Calculate TDEE
TDEE is calculated using the Mifflin-St Jeor BMR formula multiplied by an activity factor. BMR for men: 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5. For women: same but −161 instead of +5. Then multiply by your activity level (1.2 for sedentary to 1.9 for extremely active).
Step 2 — Set Protein First
Protein should be set first because it is the most important macro for body composition. Evidence consistently shows 1.6–2.2g per kg of body weight per day optimises muscle retention during a deficit and muscle gain during a surplus. At 4 calories per gram, this sets your protein calorie allocation.
Step 3 — Split Remaining Calories Between Carbs and Fat
After protein, allocate remaining calories between carbs (4 cal/g) and fat (9 cal/g) based on personal preference. A common split is 30–40% fat and 30–40% carbs from total calories. If you prefer lower carb, shift more to fat. If you train hard, more carbs support performance.
Frequently Asked Questions
How much protein do I need per day?
General guidance: 0.8g per kg of body weight for sedentary adults (the minimum RDA); 1.2–1.6g/kg for active people; 1.6–2.2g/kg for those trying to build muscle. A 75kg active person should target 120–165g protein/day.
What is IIFYM (If It Fits Your Macros)?
IIFYM is a flexible dieting approach where you track your macronutrient totals (protein, carbs, fat) rather than following rigid food rules. As long as your daily macros hit your targets, you can eat any foods you choose. It gives flexibility while maintaining nutritional structure.
How many calories are in protein, carbs and fat?
Protein = 4 calories per gram. Carbohydrates = 4 calories per gram. Fat = 9 calories per gram. Alcohol = 7 calories per gram. This is why fat-dense foods are calorie-dense despite small serving sizes.
Should I eat more carbs or fat?
It depends on your preference and how your body responds. Both can support fat loss and muscle gain if total calories and protein are right. Low-carb diets work well for some people; higher-carb diets work better for others. The key variable is total calories and adequate protein — the carb/fat split is secondary.
What macros should I eat to lose weight?
For fat loss: maintain a calorie deficit (typically 300–500 calories below TDEE), keep protein high (1.6–2g/kg) to preserve muscle, and distribute remaining calories between carbs and fat based on preference. High protein during a deficit is the most evidence-based strategy for losing fat while retaining muscle.