Macro Calculator
Calculate your daily macronutrient needs for optimal nutrition.
Personal Information
Macro Breakdown
Macro Split:
Protein: 24.1% | Carbs: 48.4% | Fats: 27.5%
About This Calculator
The Macro Calculator helps you determine your daily macronutrient needs (protein, carbohydrates, and fats) based on your body composition, activity level, and fitness goals. Understanding your macros is essential for effective nutrition planning, whether you want to lose weight, maintain, or gain muscle.
This calculator uses the Mifflin-St Jeor equation to calculate your Basal Metabolic Rate (BMR), then adjusts for activity level to determine Total Daily Energy Expenditure (TDEE). It then distributes calories across macronutrients based on optimal ratios for your goals.
Formula & Calculation Method
Macro Calculation:
BMR (Mifflin-St Jeor):
Men: BMR = 10 × Weight(kg) + 6.25 × Height(cm) - 5 × Age + 5
Women: BMR = 10 × Weight(kg) + 6.25 × Height(cm) - 5 × Age - 161
TDEE:
TDEE = BMR × Activity Multiplier
Activity Multipliers: Sedentary (1.2), Light (1.375), Moderate (1.55), Active (1.725), Very Active (1.9)
Calories:
Calories = TDEE × Goal Multiplier (Lose: 0.85, Maintain: 1.0, Gain: 1.15)
Macros:
Protein = Weight(lbs) × 1g (4 cal/g)
Fats = Calories × 27.5% (9 cal/g)
Carbs = Remaining Calories (4 cal/g)
Protein is calculated at 1g per pound of body weight for muscle maintenance and growth. Fats are set at 27.5% of total calories for hormone production and health. Carbohydrates fill the remaining calories to support energy needs.
How to Use This Calculator
- Enter Age: Input your current age in years.
- Select Gender: Choose your biological sex (affects BMR calculation).
- Enter Height: Input your height in centimeters.
- Enter Weight: Input your current weight in kilograms.
- Select Activity Level: Choose your daily activity level from sedentary to very active.
- Select Goal: Choose whether you want to lose weight, maintain, or gain weight.
- View Results: See your daily calorie needs and macro breakdown (protein, carbs, fats).
Frequently Asked Questions
What are macros?
Macros (macronutrients) are the three main nutrients your body needs in large amounts: protein (4 cal/g), carbohydrates (4 cal/g), and fats (9 cal/g). Tracking macros helps ensure you get the right balance for your goals.
How much protein do I need?
For most people, 0.8-1g per pound of body weight is recommended. Athletes and those building muscle may need 1-1.5g per pound. This calculator uses 1g per pound as a good starting point.
What percentage should my macros be?
Typical macro splits are: Protein 25-35%, Carbs 40-50%, Fats 20-30%. This calculator uses approximately 30% protein, 27.5% fats, and 42.5% carbs, which can be adjusted based on your preferences and goals.
Should I track macros or just calories?
Both have value. Calorie tracking is simpler and effective for weight management. Macro tracking provides more precision for body composition goals, muscle gain, or athletic performance. Many people start with calories and add macro tracking as needed.
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Calculator by
Dr. Michael Roberts, MD
MD (Doctor of Medicine)Board Certified in Internal Medicine