Calorie & Macro Calculator
Advanced calorie and macronutrient calculator based on Mifflin-St Jeor equations with real-time macro breakdown.
Your Profile
Your Results
Daily Maintenance Calories
2,556
TDEE (Total Daily Energy Expenditure)
Target Calories
2,556
Based on your goal
Daily Macro Breakdown
BMR
1,649 cal
Activity Factor
Moderate
Calorie & Macro Calculator — Complete User Guide
The Calorie & Macro Calculator uses the scientifically validated Mifflin-St Jeor equation to estimate your Basal Metabolic Rate (BMR) — the number of calories your body needs at complete rest to maintain basic physiological functions like breathing, circulation, and cell production.
Your Total Daily Energy Expenditure (TDEE) is calculated by multiplying your BMR by an activity factor that reflects your daily physical activity level. This gives you the total calories needed to maintain your current weight.
The calculator then applies your fitness goal: a 500-calorie deficit for weight loss (approximately 0.5kg/1lb per week), maintenance calories for weight stability, or a 500-calorie surplus for muscle gain. The macro breakdown follows evidence-based recommendations: 25% protein for muscle maintenance, 45% carbohydrates for energy, and 30% fats for hormone function and nutrient absorption.
All calculations are based on your age, gender, weight, and height. For best accuracy, enter your measurements in your preferred units and ensure your age is accurate. The calculator provides real-time updates as you adjust any input, so you can instantly see how changes affect your daily calorie and macro targets.
Understanding your personalized calorie and macro targets helps you make informed decisions about nutrition, exercise, and overall health. Whether you're looking to lose weight, maintain your current physique, or build muscle, this calculator provides the foundation for your nutrition planning. This tool is for informational purposes only and does not constitute medical advice.
Frequently Asked Questions
What are the standard macro percentages?
Standard recommendations are: Protein 20-30% of calories (for muscle maintenance), Carbohydrates 45-65% (primary energy source), and Fats 20-35% (hormone function and nutrient absorption). Our calculator uses 25% protein, 45% carbs, and 30% fats.
How accurate is the Mifflin-St Jeor equation?
The Mifflin-St Jeor equation is considered the most accurate BMR formula available, with studies showing it can be within 10% of actual measured BMR for most people. It's more accurate than the older Harris-Benedict equation.
Should I adjust macros for specific goals?
Yes, for specific goals you may want to adjust: For fat loss, increase protein to 30% and reduce carbs slightly. For muscle gain, increase carbs to 50-55% and maintain protein at 25-30%. Always consult with a nutritionist for personalized advice.
How often should I recalculate my needs?
Recalculate when you lose or gain significant weight (5-10% of body weight), change your activity level dramatically, or every 3-4 months to account for metabolic adaptations to your nutrition plan.