BMR Calculator – Calculate Your Basal Metabolic Rate | DietDekho
🔥 Metabolism Tool

Free BMR Calculator
Basal Metabolic Rate

Calculate your basal metabolic rate to discover how many calories your body burns at rest. Essential for effective diet planning and weight management.

MifflinSt Jeor Formula
AccurateResting Calorie Burn
TDEEActivity Levels
FreeDiet Guidance

Check Your BMR

Discover Your Daily Resting Calorie Needs

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Age*
15 to 80 years
⚠ Age is required (15-80)
Weight*
Current body weight
kg lb
⚠ Weight is required
Height*
Without shoes
Cm In
⚠ Height is required
💡 Tip: The Mifflin-St Jeor equation used here is considered the gold standard for calculating BMR accurately.
Understanding BMR

What is Basal Metabolic Rate (BMR)?

Basal Metabolic Rate (BMR) represents the total number of calories your body requires to accomplish its most basic, life-sustaining functions when completely at rest. These functions include processes like breathing, maintaining blood circulation, processing nutrients, and cell production. Essentially, your BMR is the baseline amount of energy your body would burn if you stayed in bed all day without moving.

BMR typically accounts for about 60% to 75% of an individual's Total Daily Energy Expenditure (TDEE), making it the largest component of your daily calorie burn.

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BMR vs. RMR

BMR (Basal Metabolic Rate) and RMR (Resting Metabolic Rate) are often used interchangeably. While BMR requires strict resting conditions (like fasting for 12 hours), RMR is a more relaxed measurement. For dietary planning, both serve the same practical purpose.

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The Calculation Method

Our calculator utilises the Mifflin-St Jeor equation, introduced in 1990. Scientific studies and the Academy of Nutrition and Dietetics recognize it as the most robust and accurate predictive equation for calculating BMR in modern individuals.

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Body Composition Matters

Muscle tissue is highly metabolically active compared to fat tissue. Individuals with a higher ratio of muscle mass to body fat will naturally have a higher BMR, burning more calories throughout the day even when completely at rest.

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Age and Metabolism

BMR naturally decreases as we age, largely due to changes in hormonal levels and a gradual reduction in lean muscle mass. Staying physically active and maintaining muscle can help offset this metabolic slowdown over time.

The Science
The Formula

How is BMR Calculated?

DietDekho's calculator uses the highly regarded Mifflin-St Jeor formula, which calculates BMR based on four key variables: weight, height, age, and biological gender. The equations are as follows:

GenderMifflin-St Jeor Equation
Males (10 × weight in kg) + (6.25 × height in cm) - (5 × age in years) + 5
Females (10 × weight in kg) + (6.25 × height in cm) - (5 × age in years) - 161
Practical Application
Applying Your BMR

How to Use BMR for Weight Management

Knowing your BMR is the crucial first step in any structured nutrition plan. Once you have calculated your BMR, you must account for your physical activity to find your Total Daily Energy Expenditure (TDEE). Here is how you can use this data:

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    Determine your TDEE: Multiply your BMR by your appropriate activity level multiplier (provided in the calculator results above). This reveals the total number of calories you burn on an average day.
  • 2
    To lower body weight: Create a sustainable calorie deficit. Consuming 300 to 500 calories below your TDEE generally leads to a steady, manageable weight reduction without compromising essential nutritional intake.
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    To increase body weight or muscle mass: Create a calorie surplus. Consuming an additional 300 to 500 calories above your TDEE, paired with strength training, provides the energy required to build new muscle tissue safely.
  • 4
    Never eat below your BMR without medical supervision: Your BMR is the baseline energy needed for your organs to function correctly. Consistently consuming fewer calories than your BMR can slow your metabolism, lead to fatigue, and cause a loss of lean muscle mass.
FAQs

Common Questions About BMR

Expert answers to the most frequently asked questions regarding metabolic rate and daily calorie consumption.

What is a "normal" or healthy BMR? +
There is no universal "normal" BMR because it heavily depends on an individual's size, muscle mass, age, and genetics. Generally, individuals with a larger body mass or high amounts of lean muscle will have a higher BMR. What matters most is using your specific BMR to properly fuel your unique body.
Can I change or increase my BMR? +
Yes. While you cannot change factors like your age or genetics, you can increase your BMR by building more lean muscle tissue through strength and resistance training. Muscle requires more energy to maintain than fat tissue, meaning a higher muscle ratio directly increases your resting calorie burn.
Why does BMR go down as we get older? +
As individuals transition into becoming older adults, BMR typically decreases. This is largely attributed to a natural reduction in muscle mass (sarcopenia) and a slowing of the body's internal processes and hormonal changes. Staying active and prioritizing protein intake can help preserve muscle and stabilize your metabolism over time.
How accurate is the BMR calculator? +
The Mifflin-St Jeor equation used in this calculator is widely considered the most accurate formula available for estimating BMR without laboratory testing. However, it remains an estimate. True BMR can only be measured accurately in a clinical setting through indirect calorimetry.
Should I eat exactly my BMR calories? +
No. You should eat based on your Total Daily Energy Expenditure (TDEE), not just your BMR. Eating exactly your BMR means you are not fueling the energy you expend through daily movement, walking, digestion, or exercise. Always factor in your activity level when determining your daily calorie goal.
Medical Disclaimer: This BMR Calculator uses the Mifflin-St Jeor equation to estimate resting metabolic rate based on generally accepted mathematical formulas. The results provided are estimates for educational and informational purposes only. They do not replace professional medical advice, diagnosis, or dietary prescription. Always consult with a registered dietitian or healthcare provider before significantly altering your caloric intake or beginning a new weight management program.