Calorie Calculator
Calculate your daily calorie needs and macro breakdown based on the Mifflin-St Jeor equation.
For informational purposes only. Not medical advice. Consult your healthcare provider.
How to Use the Calorie Calculator
Begin by selecting your unit system (imperial or metric), then enter your age, gender, height, and weight. Choose the activity level that best describes your typical week, and select your goal: lose weight, maintain weight, or gain weight. Click Calculate to see your BMR, TDEE, recommended daily calories, and a personalized macro split.
How the Mifflin-St Jeor Equation Works
The Mifflin-St Jeor equation was published in 1990 and is widely regarded by dietitians and nutritionists as the most reliable formula for estimating Basal Metabolic Rate. BMR represents the number of calories your body burns at rest to maintain basic functions like breathing, circulation, and cell production. By multiplying your BMR by an activity factor, you obtain your Total Daily Energy Expenditure (TDEE), which accounts for all daily movement and exercise.
For weight management goals, the calculator adjusts your TDEE by subtracting 500 calories per day for weight loss (approximately 1 pound per week) or adding 500 calories for weight gain. These adjustments are considered safe and sustainable for most adults. For more aggressive goals, consult a healthcare professional.
Understanding Macronutrients
The macro split determines how your calories are distributed among protein, carbohydrates, and fat. Protein is essential for muscle repair and growth, carbohydrates provide energy for daily activities and exercise, and healthy fats support hormone production and nutrient absorption. The default split of 30% protein, 40% carbs, and 30% fat works well for most people, but you can adjust the percentages to match your dietary preferences or specific fitness goals.
Tips for Accurate Results
Be honest about your activity level, as this is the most common source of error. Most people overestimate their activity, which leads to eating too many calories. If you are unsure, start with the lower activity level and adjust based on results after a few weeks. Track your weight weekly rather than daily, as daily fluctuations are normal and can be misleading.
Remember that calorie calculators provide estimates, not exact numbers. Individual metabolism varies based on genetics, body composition, sleep quality, stress levels, and many other factors. Use these numbers as a starting point and fine-tune based on your body's response over time.
Medical Disclaimer: This calculator provides general health information only and is not a substitute for professional medical advice. Consult your healthcare provider for personalized guidance.