BMR Calculator: Calculate Your Basal Metabolic Rate and Daily Calorie Requirement

A BMR Calculator helps you understand how many calories your body needs to maintain its basic functions — like breathing, circulation, and cell repair — even when you’re at rest. Knowing your BMR is the first step toward achieving your weight loss, maintenance, or muscle gain goals.

What is BMR?

Basal Metabolic Rate (BMR) represents the number of calories your body burns while at complete rest. It forms the foundation for calculating your Total Daily Energy Expenditure (TDEE), which accounts for activity, exercise, and lifestyle.

BMR Formula

The **Mifflin-St Jeor Equation** is considered the most accurate BMR formula:

Men:    BMR = 88.36 + (13.4 × weight in kg) + (4.8 × height in cm) − (5.7 × age)
Women:  BMR = 447.6 + (9.2 × weight in kg) + (3.1 × height in cm) − (4.3 × age)

Activity Levels and Calorie Multipliers

• Sedentary (1.2): Little or no exercise
• Lightly Active (1.375): Light exercise 1–3 days/week
• Moderately Active (1.55): Moderate exercise 3–5 days/week
• Very Active (1.725): Hard exercise 6–7 days/week
• Super Active (1.9): Intense physical training twice daily

Why Knowing Your BMR is Important

• Helps create personalized diet and workout plans.
• Assists in determining calorie intake for fat loss or muscle gain.
• Prevents overeating and undernutrition.
• Optimizes metabolism and improves long-term health.

BMR vs. TDEE

BMR is the base calorie requirement at rest. TDEE (Total Daily Energy Expenditure) = BMR × Activity Factor. TDEE gives a more accurate picture of your daily calorie burn.

Tips for Managing Your Metabolism

• Eat enough protein to maintain muscle mass.
• Stay hydrated — metabolism slows with dehydration.
• Do regular strength training and cardio.
• Get 7–8 hours of quality sleep per night.

Frequently Asked Questions (FAQs)

Does BMR change with age?

Yes, BMR tends to decrease as you age due to loss of muscle mass and slower metabolism.

Can exercise increase BMR?

Regular exercise, especially strength training, can help boost your BMR by increasing lean muscle.

What if I eat below my BMR?

Consistently eating below your BMR can cause fatigue, nutrient deficiencies, and slow metabolism. It’s not sustainable for long-term health.

Conclusion

The BMR Calculator is a crucial tool for anyone looking to manage their weight effectively. By knowing how many calories your body naturally burns, you can tailor your nutrition and fitness plan to meet your goals. Track your BMR regularly and stay mindful of your activity to maintain optimal health and energy.