Calculate your daily protein, carbs, and fat for weight loss, muscle gain, or maintenance.
Enter your age, sex, height, weight, and activity level, then select your goal (cut, maintain, or bulk). Optionally enter your body fat percentage for more accurate lean mass calculations. Hit Calculate My Macros to get your personalized daily calorie target and exact protein, carbohydrate, and fat targets in grams.
Tracking macros — not just calories — is one of the most effective strategies for changing body composition. A 200-lb man trying to lose fat and preserve muscle needs vastly different macros than someone of the same weight trying to add 20 lbs of lean mass. The difference isn't just calories; it's how those calories are distributed.
For example: a 175-lb person at moderate activity trying to cut might target 2,100 calories with 175g protein, 210g carbs, and 58g fat. That same person bulking could eat 2,800 calories with similar protein but significantly more carbs to fuel workouts and support recovery. Without hitting protein targets, calorie restriction leads to muscle loss — the opposite of what most people want.
Athletes, bodybuilders, busy professionals trying to lose weight, and anyone who's struggled with yo-yo dieting all benefit from macro tracking. Research consistently shows that higher protein intake (0.8–1.2g per lb of lean body mass) dramatically improves fat loss results while preserving or building muscle.
This calculator uses the Mifflin-St Jeor equation to estimate Basal Metabolic Rate (BMR), widely considered the most accurate formula for the general population:
BMR is multiplied by an activity multiplier (1.2–1.9) to get TDEE (Total Daily Energy Expenditure). Then a calorie adjustment is applied: −500 kcal for cutting, 0 for maintenance, +300 kcal for lean bulking. Protein is set first (based on lean body mass), fat at ~25% of calories, and the remaining calories are filled with carbohydrates.
Macros (macronutrients) are the three main categories of nutrients that provide calories: protein (4 kcal/g), carbohydrates (4 kcal/g), and fat (9 kcal/g). Tracking macros matters because each plays a different role — protein builds and repairs muscle, carbs fuel energy and workouts, and fat supports hormones and nutrient absorption. Hitting the right ratio helps you achieve specific body composition goals, not just weight changes.
The Mifflin-St Jeor equation is accurate within ±10% for most people, making it the gold standard in clinical settings. Results are estimates — genetics, hormones, sleep quality, and stress all affect real-world metabolism. Use these numbers as a starting point, track your actual results for 2–3 weeks, and adjust accordingly.
For most people, using a weekly average calorie target is simpler and equally effective. If you train intensely 4+ days per week, carb cycling (eating more carbs on training days, fewer on rest days) can optimize performance and recovery. A good starting point: add 100–200 extra grams of carbs on heavy training days and reduce by the same on rest days, keeping weekly totals consistent.
Leave the field blank — the calculator will estimate it using established population averages based on your BMI and sex. For more accuracy, you can measure body fat using a DEXA scan, hydrostatic weighing, or a reliable body fat caliper measurement using the Navy or Jackson-Pollock methods. Even a rough estimate significantly improves protein target accuracy compared to using total bodyweight.