BMR Calculator

A BMR (Basal Metabolic Rate) calculator is an online tool that estimates the number of calories your body burns at complete rest to maintain vital functions like breathing, circulation, cell production, and temperature regulation. Whether you're planning weight loss, maintaining weight, or optimizing nutrition, understanding your BMR provides the foundation for all calorie calculations and dietary planning.

This calculator uses scientifically validated formulas like the Mifflin-St Jeor equation to estimate your BMR based on age, gender, height, and weight. It also calculates your Total Daily Energy Expenditure (TDEE) by multiplying BMR by your activity level, giving you a complete picture of your daily calorie needs including both resting metabolism and physical activity.

Understanding your BMR is crucial for effective weight management and nutrition planning. Your BMR represents the minimum calories your body needs just to stay alive, accounting for 60-75% of total daily calorie expenditure for most people. This baseline helps you set realistic calorie targets that ensure you meet minimum energy needs while achieving fitness goals safely.

Nutritionists and dietitians use BMR calculations as the starting point for personalized meal planning, ensuring clients don't under-eat to dangerous levels. Fitness professionals use TDEE (BMR × activity factor) to prescribe appropriate calorie intakes for fat loss, muscle gain, or athletic performance. Understanding your metabolic rate also helps explain why calorie needs vary dramatically between individuals of different sizes and ages.

The tool ensures accuracy by using peer-reviewed equations, provides instant personalized results, and helps prevent extreme calorie restriction that can damage metabolism. It's particularly valuable when starting a diet, adjusting intake after plateaus, understanding why previous diets failed, or setting evidence-based nutrition goals.

Weight Loss Planning: Determine minimum safe calorie intake by ensuring you never eat below your BMR, preventing metabolic slowdown and health issues.

Nutrition Baseline: Establish your baseline calorie needs before adding activity calories to calculate total daily energy expenditure (TDEE).

Metabolic Understanding: Understand how factors like age, gender, and body size affect your metabolism and calorie needs throughout life.

Diet Comparison: Evaluate whether popular diet calorie recommendations are appropriate and safe for your specific metabolic needs.

Health Monitoring: Track how metabolism changes with age, muscle mass changes, or metabolic conditions to adjust nutrition accordingly.

Using our BMR calculator is straightforward: enter your age, gender, height, and weight. The calculator instantly provides your BMR (calories burned at rest) and TDEE estimates for different activity levels (sedentary to extremely active). This helps you understand both your baseline metabolism and real-world daily calorie needs.

The calculator uses the Mifflin-St Jeor equation, currently the most accurate BMR formula: For men: BMR = (10 × weight in kg) + (6.25 × height in cm) - (5 × age) + 5. For women: BMR = (10 × weight in kg) + (6.25 × height in cm) - (5 × age) - 161. TDEE = BMR × Activity Factor (1.2 for sedentary to 1.9 for extremely active). Your BMR represents the minimum calories needed daily; always eat at least this amount to maintain healthy metabolism. All calculations are performed locally in your browser for privacy.