How to Calculate Your Macros for Any Goal

Macros are the three nutrients that supply energy: protein and carbohydrate at about 4 calories per gram, and fat at about 9. Setting macro targets is a two-step process. First you estimate how many calories you need, then you split those calories among the three nutrients according to your goal.

The most widely used calorie estimate is the Mifflin-St Jeor equation, which calculates your basal metabolic rate, the energy your body uses at rest. For men it is 10 times weight in kilograms plus 6.25 times height in centimeters minus 5 times age in years, plus 5. For women the final term is minus 161 instead of plus 5.

Your BMR is multiplied by an activity factor, roughly 1.2 for sedentary up to about 1.9 for very hard training, to give total daily energy expenditure (TDEE), an estimate of maintenance calories. To lose weight you eat below that number; to gain you eat above it. A moderate deficit or surplus of around 15 to 20 percent is a common, sustainable starting point.

From there, protein is often set first because it preserves muscle and keeps you full, commonly around 1.6 to 2.2 grams per kilogram of body weight for active people. Fat is usually kept at a minimum of about 0.6 to 1 gram per kilogram for hormone health, and carbohydrate fills the remaining calories to fuel training.

The tool runs the equation and the split for you so you can adjust inputs and see targets update.

Every equation is an estimate. Mifflin-St Jeor is accurate for most people but can be off by a few hundred calories, and it does not know your exact body composition, genetics, or how honestly you logged your activity. The real test is what happens over two or three weeks: if your weight is not moving the way you intended, adjust calories by a small amount and reassess.

Macros are a tool for consistency, not a moral scorecard, and hitting them within a reasonable range beats obsessing over single grams. If you have a medical condition, are pregnant, or are managing an eating disorder history, work with a doctor or registered dietitian before setting deficit or surplus targets.