Calculate your daily protein, carbs, and fat targets based on your body, activity level, and goal. Powered by the Mifflin-St Jeor formula.
−500 cal/day
Protein 40% · Carbs 30% · Fat 30%
High protein preserves muscle during a deficit. Lower carbs reduce insulin spikes and help control hunger.
TDEE calories
Protein 30% · Carbs 40% · Fat 30%
Balanced distribution to sustain current body composition, energy, and performance.
+300 cal/day
Protein 35% · Carbs 45% · Fat 20%
Higher carbs fuel workouts and recovery. Elevated protein supports hypertrophy with minimal fat gain.
+500 cal/day
Protein 25% · Carbs 50% · Fat 25%
Aggressive surplus maximizes muscle and strength gains. Best for hard gainers and strength athletes.
Macronutrients — protein, carbohydrates, and fat — are the three building blocks of every meal. Unlike micronutrients (vitamins and minerals), macros are the primary sources of calories and energy. Your body uses them for different functions: protein repairs and builds tissue, carbohydrates fuel your brain and muscles, and fat supports hormones and absorbs fat-soluble vitamins.
Calorie counting tells you how much you eat. Macro tracking tells you what you eat. Two people can both eat 2,000 calories, yet one gets 150g of protein and the other only 60g — leading to very different body composition outcomes. Tracking macros is the single most effective nutritional strategy for changing your body composition deliberately.
This macro calculator uses the Mifflin-St Jeor equation — the gold standard endorsed by the Academy of Nutrition and Dietetics — to calculate your Basal Metabolic Rate (BMR). BMR is then multiplied by an activity factor to get your Total Daily Energy Expenditure (TDEE). A goal-based calorie adjustment is applied, and the result is split into macros using evidence-based percentages.
Men: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5
Women: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) − 161
TDEE = BMR × Activity Multiplier. The activity multipliers used are: Sedentary (1.2), Lightly active (1.375), Moderately active (1.55), Very active (1.725), Extra active (1.9).
Once your target calories are set, they are distributed across the three macronutrients. Each gram of protein and carbohydrate contains 4 calories; each gram of fat contains 9 calories. The table below shows the splits used by this calculator:
| Goal | Calorie Adjustment | Protein | Carbs | Fat |
|---|---|---|---|---|
| Lose Fat | −500 cal/day | 40% | 30% | 30% |
| Maintain | 0 | 30% | 40% | 30% |
| Build Muscle | +300 cal/day | 35% | 45% | 20% |
| Bulk | +500 cal/day | 25% | 50% | 25% |
Protein is the most important macro for body composition. Research consistently shows that higher protein intakes — around 1.6–2.2 g per kg of body weight — maximize muscle protein synthesis. Higher intakes (up to 3 g/kg) are safe and can be beneficial for very active individuals or those in a large calorie deficit, as excess protein is thermogenic (your body burns ~25% of its calories just to digest it).
Common protein targets by goal:
Despite decades of low-carb fad diets, carbohydrates are not inherently fattening. They are the body's preferred energy substrate, especially for the brain and during high-intensity exercise. The type and timing of carbs matters more than the amount. Whole-food carb sources — oats, rice, sweet potatoes, legumes, fruit — provide fiber, micronutrients, and sustained energy.
For weight loss, reducing carbs lowers total calories and can reduce appetite for some people. For muscle building, higher carb intake improves workout performance and speeds up glycogen replenishment between sessions. The "best" carb intake is the one that supports your performance and fits within your calorie budget.
Fat is the most calorie-dense macro at 9 kcal/g, but it plays critical roles: producing hormones (including testosterone and estrogen), absorbing vitamins A, D, E, and K, and maintaining cell membrane integrity. Fat also slows gastric emptying, which reduces hunger and stabilizes blood sugar.
Prioritize unsaturated fats (olive oil, avocado, nuts, fatty fish) over saturated fats, and minimize trans fats. A fat intake below 20% of total calories can negatively affect hormonal health, so the 20–30% range used in this calculator is both safe and practical.
Your calculated macros are a starting point, not an immovable target. Here is a practical approach:
The biggest challenge with macro tracking is consistency, not calculation. Here are the strategies that work:
Build the habit of daily macro tracking with Brite. Set goals, log meals, and track your nutrition streak — all in one free app.
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