Basal Metabolic Rate (BMR) refers to the amount of energy (calories) your body requires to carry out its most basic life-sustaining functions — such as breathing, blood circulation, cell repair, hormone production, and temperature regulation — while at complete rest.

In simpler terms, your BMR is the number of calories your body burns at rest to keep you alive and functioning. Around 60–70% of your daily energy expenditure comes from your basal metabolism.

While many people focus on the number on the weighing scale to measure progress, understanding your BMR gives a far more accurate picture of how your metabolism works — helping you plan your diet and workouts effectively.

A BMR Calculator is an online tool that helps estimate the number of calories your body burns while at rest. It calculates the kilocalories required to maintain vital body functions like respiration and heart rate — even when you’re not engaging in any physical activity.

For accurate results, BMR is ideally measured after 12 hours of fasting, a full night’s sleep, and no physical or emotional stress, as these factors can temporarily alter metabolic rate.

Your Basal Metabolic Rate gives you insight into how efficiently your body uses energy. Knowing your BMR helps you:

• • Set realistic weight management goals (gain, lose, or maintain weight)
• • Determine your daily calorie intake
• • Plan balanced diet and exercise routines
• • Avoid caloric deficit or surplus that can affect metabolism

By understanding your BMR, you can make informed decisions about how many calories to consume or burn for optimal health and sustainable results.

For Men: BMR = 88.362 + (13.397 × weight in kg) + (4.799 × height in cm) – (5.677 × age in years)

For Women: BMR = 447.593 + (9.247 × weight in kg) + (3.098 × height in cm) – (4.330 × age in years)

Note: The Harris-Benedict formula provides an estimate of your BMR. Factors such as muscle mass, body composition, diet, weather, genetics, pregnancy, and medication can affect your actual metabolic rate.

Several factors can influence how fast or slow your metabolism functions:

1. Body Size and Surface Area

Taller or larger individuals have more metabolically active tissue, leading to a higher BMR.

2. Age

As we age, our metabolism slows due to reduced muscle mass and hormonal changes. After age 20, BMR tends to decrease by around 2% per decade.

3. Gender

Men generally have a 10–15% higher BMR than women because of higher lean muscle mass.

4. Body Fat Percentage

Muscle tissue burns more calories than fat. A higher body fat percentage means a lower BMR.

5. Growth and Development

Infants and children require more calories per kilogram of body weight to support rapid growth.

6. Genetics

Your metabolic efficiency may be influenced by hereditary factors.

7. Hormonal Balance

Thyroid hormones (especially thyroxine) significantly affect metabolism. High levels increase BMR, while low levels reduce it.

8. Diet and Caloric Intake

Crash dieting, fasting, or extreme calorie restriction can slow down metabolism, while a balanced diet maintains it.

9. Pregnancy

Metabolism increases during pregnancy to support fetal growth and development.

10. Medications and Stimulants

Certain drugs like caffeine, nicotine, steroids, and antidepressants can alter BMR — either raising it or causing weight gain by affecting energy regulation.

11. Body Temperature and Environment

For every 1°C increase in body temperature, BMR rises by about 10–15%. Extreme heat or cold also increases metabolic activity as the body works to maintain homeostasis.

12. Illness or Infection

During illness, your body burns more energy for tissue repair and immune defense, temporarily increasing BMR.

13. Lean Muscle Mass & Physical Activity

Lean muscles are metabolically active and burn more calories even at rest. Regular physical activity helps maintain higher BMR by increasing muscle mass and efficiency.

Though often used interchangeably, BMR and RMR (Resting Metabolic Rate) are slightly different:

In short, BMR measures calories burned in complete rest, while RMR includes minimal movement or non-exercise activities.

To calculate your BMR manually or with our online tool, enter your:

• Gender
• Weight (kg)
• Height (cm)
• Age (years)
• Activity Level (e.g., sedentary, moderate, active)

Once calculated, your BMR value shows how many calories your body burns at rest. You can then multiply this number by your activity level to determine your Total Daily Energy Expenditure (TDEE) — the total calories you need daily to maintain your current weight.

Your Basal Metabolic Rate is the foundation of your energy balance. It helps you understand how many calories your body needs to stay alive and function efficiently.

A BMR Calculator gives you a starting point for your fitness journey — whether your goal is weight loss, muscle gain, or maintenance. Though not 100% precise, it provides a reliable baseline to guide your diet and training plan.

For personalized advice, consult our certified nutritionist to get your BMR assessed accurately and receive a custom calorie and meal plan suited to your goals.