Macronutrient Calculator
How to Calculate Your Macronutrients
Understanding your macronutrient needs is the foundation of any successful nutrition plan. Whether your goal is to lose body fat, build lean muscle, or improve athletic performance, the balance of protein, carbohydrates, and fats determines your body composition and energy levels.
The Science Behind the Calculation
This calculator uses the Mifflin-St Jeor Equation, widely considered the most accurate formula for calculating Basal Metabolic Rate (BMR) for the general population. Here is how the process works:
- Step 1: Basal Metabolic Rate (BMR): This is the number of calories your body burns at rest just to keep your organs functioning. It is based on your weight, height, age, and biological sex.
- Step 2: Total Daily Energy Expenditure (TDEE): We multiply your BMR by an activity factor (ranging from 1.2 to 1.9) to account for calories burned during movement and exercise.
- Step 3: Goal Adjustment: To lose weight, we typically subtract 500 calories from your TDEE. To gain weight, we add 500 calories.
Understanding the Three Macros
Once your calorie target is established, we split those calories into three categories:
Protein (4 kcal per gram): Essential for muscle repair and hormone production. Our calculator targets 30% of your calories from protein to support muscle retention and satiety.
Carbohydrates (4 kcal per gram): Your body's primary energy source. We allocate 45% of your intake to carbs to fuel your brain and workouts.
Fats (9 kcal per gram): Vital for brain health and vitamin absorption. We set fats at 25% of your total intake to ensure hormonal health while keeping calories in check.
Example Calculation
Consider a 30-year-old male, weighing 80kg at 180cm tall with a moderate activity level. His BMR would be roughly 1,780 calories. Multiplied by an activity factor of 1.55, his maintenance calories (TDEE) would be 2,759. If his goal is weight loss, his target becomes 2,259 calories. Using a balanced ratio, his macros would be approximately 170g Protein, 254g Carbs, and 63g Fat.