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BMR Calculator

Calculate Basal Metabolic Rate (BMR) - calories your body burns at rest. Use Mifflin-St Jeor or Harris-Benedict formula based on age, gender, weight, and height for metabolism estimation.

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BMR Calculator: Understanding Basal Metabolic Rate

Basal Metabolic Rate (BMR) is the number of calories your body burns at complete rest to maintain vital functions like breathing, circulation, cell production, and nutrient processing. BMR accounts for 60-75% of your total daily calorie expenditure and represents the minimum energy required to keep your body functioning. Understanding your BMR is the foundation for calculating your Total Daily Energy Expenditure (TDEE) and planning effective nutrition strategies.

BMR Formulas: The Mifflin-St Jeor equation is considered the most accurate: For men: BMR = 10 × weight(kg) + 6.25 × height(cm) - 5 × age(years) + 5. For women: BMR = 10 × weight(kg) + 6.25 × height(cm) - 5 × age(years) - 161. The older Harris-Benedict equation is still widely used but tends to overestimate BMR by 5-10%. For example, a person weighing 70kg, height 170cm, age 30, male: BMR = (10 × 70) + (6.25 × 170) - (5 × 30) + 5 = 700 + 1,062.5 - 150 + 5 = 1,617.5 kcal/day.

Example: A person weighing 70kg, height 170cm, age 30, using the Mifflin-St Jeor formula: For a male, BMR ≈ 1,618 kcal/day. For a female, BMR ≈ 1,452 kcal/day. This represents the calories needed at complete rest. When you add activity (multiply by activity level), you get TDEE. For instance, if this person is moderately active (×1.55), their TDEE would be approximately 2,508 kcal/day (male) or 2,251 kcal/day (female). Our calculator uses the most accurate formulas to help you understand your metabolism and plan your nutrition accordingly.

🔥 BMR Calculator

Calculate your Basal Metabolic Rate (BMR) - the number of calories your body burns at complete rest. Use the accurate Mifflin-St Jeor equation to find your baseline metabolism for effective weight management and nutrition planning.

📊 Mifflin-St Jeor Formula
🔥 Calories at Rest
💪 Weight Management
📈 TDEE Calculation

Enter Your Information

Enter your age, gender, weight, and height to calculate your BMR

👤 Gender

Enter weight in kilograms

Enter height in centimeters

Your BMR Results

Basal Metabolic Rate (BMR)
1618 calories/day

Your BMR is 1618 calories per day. This is the number of calories your body burns at complete rest to maintain vital functions like breathing, circulation, and cell production.

Calorie Burn Over Time

Daily (at rest)
1618 cal
Weekly (at rest)
11,323 cal
Monthly (at rest)
48,525 cal

📊 Formula Used

Mifflin-St Jeor Equation:

(10 × weight) + (6.25 × height) - (5 × age) + 5

Where: weight in kg, height in cm, age in years

What's Next?

💡 Using Your BMR

Your BMR is just the starting point. To find out how many calories you burn with daily activities, you need to calculate your TDEE (Total Daily Energy Expenditure) by multiplying your BMR by your activity level:

  • •Sedentary (little/no exercise): BMR × 1.2
  • •Lightly Active (1-3 days/week): BMR × 1.375
  • •Moderately Active (3-5 days/week): BMR × 1.55
  • •Very Active (6-7 days/week): BMR × 1.725
  • •Extra Active (physical job + exercise): BMR × 1.9

👉 Use our TDEE Calculator for complete calorie needs based on your activity level!

Understanding Basal Metabolic Rate (BMR)

Your Basal Metabolic Rate (BMR) is the number of calories your body needs to perform basic, life-sustaining functions at complete rest. This includes breathing, circulating blood, controlling body temperature, cell growth and repair, and brain and nerve functions.

What Affects Your BMR?

  • Body Composition: Muscle tissue burns more calories than fat tissue, even at rest
  • Age: BMR typically decreases about 2% per decade after age 20
  • Gender: Men generally have higher BMR due to greater muscle mass
  • Height/Weight: Larger bodies require more energy for basic functions
  • Genetics: Some people naturally have faster or slower metabolism
  • Hormones: Thyroid and other hormones significantly affect BMR

How to Use Your BMR for Weight Management

  • Maintain Weight: Consume calories equal to your TDEE
  • Lose Weight: Create a deficit of 500-1000 calories below TDEE
  • Gain Weight: Create a surplus of 300-500 calories above TDEE
  • Never go below BMR: Eating below BMR can slow metabolism and cause health issues

The Mifflin-St Jeor Equation

This calculator uses the Mifflin-St Jeor equation, developed in 1990 and considered the gold standard for BMR calculation. It's more accurate than the older Harris-Benedict equation, especially for modern populations and overweight individuals.

Important Considerations

  • BMR calculations are estimates; actual metabolism varies by individual
  • Medical conditions can significantly affect BMR
  • Medications may increase or decrease metabolic rate
  • Very low calorie diets can lower BMR (starvation mode adaptation)
  • BMR is highest in growing children and decreases with age
  • For precise measurements, consider metabolic testing at a lab
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Important Health Disclaimer

This BMR calculator is provided for informational and educational purposes only. The calculations and estimates are based on the Mifflin-St Jeor equation and the inputs provided, and should not be considered as medical, nutritional, or health advice. Actual BMR, metabolic rate, calorie needs, and other factors may vary significantly based on individual genetics, medical conditions, medications, body composition, hormonal factors, and other variables. BMR calculations are estimates and may not be accurate for everyone, especially those with medical conditions, athletes, or individuals with unusual body compositions. We strongly recommend consulting with qualified healthcare professionals, registered dietitians, certified nutritionists, and physicians before making significant changes to your diet, exercise routine, or weight management plan. This calculator is not a substitute for professional medical advice, diagnosis, or treatment.

Frequently Asked Questions

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Medical & Health Advice Disclaimer

Important: This BMR (Basal Metabolic Rate) Calculator is an estimation tool only and does not provide medical advice, diagnosis, or treatment recommendations.

Not a Substitute for Medical Consultation: The BMR calculations and calorie estimates provided by this calculator are for informational and planning purposes only. They should not be used as a substitute for professional medical advice, diagnosis, or treatment from a qualified healthcare provider, registered dietitian, or certified nutritionist.

Individual Results May Vary: Actual BMR, metabolism, and calorie needs vary significantly based on individual medical history, genetics, muscle mass, hormones, medications, health conditions, and other factors. The estimates provided are general calculations and may not reflect your actual metabolic rate or calorie needs.

Consult a Healthcare Professional: Always consult with a licensed healthcare provider, registered dietitian, or certified nutritionist before starting any diet, exercise program, or making significant changes to your calorie intake, especially if you have existing health conditions, take medications, or are pregnant or breastfeeding.

No Medical Guarantees: This calculator does not guarantee weight loss, weight gain, or health outcomes. Individual results vary based on numerous factors including adherence to diet and exercise, metabolism, and individual response.

Calculate your Basal Metabolic Rate (BMR) - the calories your body burns at rest - using our free BMR calculator. Use Mifflin-St Jeor or Harris-Benedict formulas based on age, gender, weight, and height. Perfect for understanding your metabolism, planning calorie intake, and creating effective weight management strategies.

✅ Common Use Cases

  • Understand your metabolism and calorie needs at rest
  • Calculate base calories for weight loss or gain plans
  • Determine calorie requirements for different activity levels
  • Plan nutrition based on metabolic rate

💡 Key Benefits

  • Mifflin-St Jeor and Harris-Benedict formula options
  • Accurate BMR calculation for men and women
  • Activity level multipliers for TDEE calculation
  • Metabolism understanding for weight management

How to Use BMR Calculator

1️⃣

Choose your calculator

Navigate to the BMR Calculator page and familiarize yourself with the input fields.

2️⃣

Enter your values

Input your data into the calculator fields. All inputs are validated in real-time.

3️⃣

View instant results

The calculator instantly displays comprehensive results with detailed breakdowns.

🔬 How BMR Calculator Works

📐 Formula

BMR Calculator Calculation Formula: The BMR Calculator employs validated mathematical formulas and computational algorithms specifically designed for health and fitness calculations involving body metrics, nutrition, and wellness tracking. The calculation process takes your input values and applies industry-standard formulas to produce accurate, reliable results. Each input parameter influences the final result according to established mathematical principles, ensuring consistency and accuracy across all calculations.

Variables:

  • Input Values: The specific data points you provide to the BMR Calculator, such as amounts, rates, measurements, or other relevant parameters needed for the calculation
  • Calculation Function: The mathematical formula or algorithm that processes your inputs according to established principles and industry standards
  • Result: The calculated output value, which may include primary results, intermediate calculations, and detailed breakdowns to help you understand the computation

📋 Step-by-Step Calculation Process

1

Gather Required Information

Before using the BMR Calculator, identify all the values you need for the calculation. Review the input fields to understand what information is required, including units of measurement, time periods, or other relevant parameters. Having accurate input data ensures reliable results.

2

Enter Your Values

Input your information into the BMR Calculator fields. The calculator provides clear labels, helpful placeholders, and real-time validation to guide you. As you type, the calculator checks for valid inputs and highlights any errors immediately, ensuring you enter correct values before calculation.

3

Review and Verify Inputs

Double-check all entered values for accuracy. Verify that numbers are correct, units match (e.g., dollars vs. cents, months vs. years), and all required fields are filled. The calculator will alert you to any missing or invalid inputs before proceeding with calculations.

4

Calculate and Analyze Results

The BMR Calculator processes your inputs instantly using validated formulas and algorithms. Results appear immediately with detailed breakdowns, intermediate calculations, and clear explanations. Review all result metrics to fully understand the calculation and its implications for your specific situation.

5

Interpret and Apply Results

Use the detailed result breakdowns and explanations to understand what the calculations mean for your situation. Compare different scenarios by adjusting inputs, and use the insights gained to make informed decisions. The calculator provides context and explanations to help you interpret results accurately.

⌨️ Understanding Input Fields

Primary Input ValuesVaries by calculator type

The main data points required for the BMR Calculator calculation. These values typically include amounts, rates, time periods, measurements, or other parameters specific to health and fitness calculations involving body metrics, nutrition, and wellness tracking. Each input field is clearly labeled with its purpose and expected format.

💡 Tip:Ensure all inputs are accurate, use consistent units throughout, and double-check decimal places. The calculator validates inputs in real-time and provides helpful error messages if values are invalid or outside expected ranges.
Additional ParametersVaries

Optional or secondary inputs that may affect the calculation results. These parameters allow you to customize the calculation for your specific needs and compare different scenarios.

💡 Tip:Experiment with different parameter values to see how they affect results. This helps you understand the relationship between inputs and outputs and make more informed decisions.

📊 Understanding Your Results

The BMR Calculator delivers comprehensive calculation results with detailed breakdowns and clear explanations. Each result metric is labeled and explained to help you understand not just what the numbers are, but what they mean for your specific situation. The calculator provides context, comparisons, and actionable insights based on health and fitness calculations involving body metrics, nutrition, and wellness tracking principles, enabling you to make informed decisions with confidence.

Key Metrics Explained:

  • Primary Calculation Result: The main output value from the BMR Calculator, representing the primary calculation you requested. This result is calculated using validated formulas and algorithms, ensuring accuracy and reliability. Understanding this primary result helps you make informed decisions about health and fitness calculations involving body metrics, nutrition, and wellness tracking.
  • Supporting Calculations: Additional metrics and breakdowns that provide context and deeper insights into the BMR Calculator results. These supporting calculations help you understand the complete picture, including intermediate values, percentages, comparisons, and other relevant metrics that enhance your understanding of the primary result.
  • Detailed Breakdowns: Comprehensive explanations and step-by-step breakdowns showing how the BMR Calculator arrived at each result. These breakdowns help you verify calculations, understand the underlying formulas, and gain confidence in the results for health and fitness calculations involving body metrics, nutrition, and wellness tracking.

What to Do Next:

  • Review the results carefully to ensure they match your expectations
  • Use the results to make informed decisions or plan next steps
  • Experiment with different input values to see how they affect results
  • Share or save results for future reference if needed

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