BMR Calculator

- May 09, 2025
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Calculate your Basal Metabolic Rate (BMR) - the number of calories your body needs at rest to maintain basic functions.

Personal Information

Calculation Method

Activity Level

Goal

Display Options

About Basal Metabolic Rate (BMR)

Basal Metabolic Rate (BMR) is the number of calories your body needs while resting, to maintain basic functions such as breathing, circulation, and cell production.

BMR Calculation Methods
  • Mifflin-St Jeor Equation: Considered the most accurate formula for estimating BMR.
    • For men: BMR = 10W + 6.25H - 5A + 5
    • For women: BMR = 10W + 6.25H - 5A - 161
    Where W is weight in kg, H is height in cm, and A is age in years.
  • Harris-Benedict Equation: An older but still widely used formula.
    • For men: BMR = 13.397W + 4.799H - 5.677A + 88.362
    • For women: BMR = 9.247W + 3.098H - 4.330A + 447.593
  • Katch-McArdle Formula: Takes into account lean body mass, which can be more accurate for those who know their body fat percentage.
    • BMR = 370 + (21.6 × LBM)
    • Where LBM is lean body mass in kg = Weight - (Weight × Body Fat %)
Total Daily Energy Expenditure (TDEE)

TDEE is your BMR multiplied by an activity factor:

  • Sedentary (little or no exercise): BMR × 1.2
  • Lightly active (light exercise 1-3 days/week): BMR × 1.375
  • Moderately active (moderate exercise 3-5 days/week): BMR × 1.55
  • Very active (hard exercise 6-7 days/week): BMR × 1.725
  • Extra active (very hard exercise & physical job): BMR × 1.9
Using BMR for Weight Management

Understanding your BMR and TDEE can help you manage your weight:

  • Weight Maintenance: Consume your TDEE calories
  • Weight Loss: Consume fewer calories than your TDEE
  • Weight Gain: Consume more calories than your TDEE

A calorie deficit of approximately 3,500 calories is equivalent to losing about 1 pound (0.45 kg) of body fat.

Factors Affecting BMR
  • Age: BMR decreases with age
  • Gender: Men generally have a higher BMR than women
  • Body Composition: Higher muscle mass increases BMR
  • Genetics: Family history can affect your metabolic rate
  • Hormones: Thyroid issues and other hormonal conditions can affect BMR
  • Health Status: Various illnesses can impact BMR
  • Climate: Living in extreme climates may increase BMR

Understanding the BMR Calculator

The BMR Calculator is a handy tool that estimates your Basal Metabolic Rate (BMR). This is the number of calories your body needs while at rest to perform essential functions. Knowing your BMR can help you manage your weight better, whether your goal is to lose, gain, or maintain weight. It takes into account various factors like age, gender, weight, height, and activity level to give you a personalised result.

Why BMR Matters for Your Health

Your BMR is crucial because it reflects the minimum energy your body needs to function. This includes processes like:

  • Breathing
  • Circulation of blood
  • Cell production
  • Regulating body temperature

Understanding your BMR can help you create a diet and exercise plan that suits your lifestyle. By knowing how many calories you burn at rest, you can make informed decisions about what to eat and how much to exercise.

How to Use the BMR Calculator

The BMR Calculator is user-friendly. You simply input personal details such as your gender, age, weight, and height. You also select your activity level and weight goals. This information helps the calculator determine your unique BMR and total daily energy expenditure (TDEE).

Calculation Methods Explained

There are different formulas used to calculate BMR, and each has its strengths. The BMR Calculator allows you to choose from several methods, including:

  • Mifflin-St Jeor Equation: Widely regarded as the most accurate.
  • Harris-Benedict Equation: An older method still in common use.
  • Katch-McArdle Formula: Best for those who know their body fat percentage.

These methods offer distinct advantages depending on your individual needs and data available.

What Influences Your BMR?

Several factors can affect your BMR. These include your:

  • Age: BMR tends to decrease as you get older.
  • Gender: Men usually have a higher BMR than women.
  • Body composition: More muscle means a higher BMR.
  • Health status: Certain health conditions can influence metabolism.

Understanding these factors can help you interpret your BMR results more effectively.

Using BMR for Weight Management

Once you know your BMR, you can use it to manage your weight goals. Here’s how:

  • For weight maintenance, consume calories equal to your TDEE.
  • To lose weight, eat fewer calories than your TDEE.
  • For weight gain, increase your calorie intake beyond your TDEE.

This approach allows you to tailor your caloric intake based on your personal goals.

Setting Goals with the BMR Calculator

The calculator also helps you set realistic goals depending on your desired weight changes. You can choose options like mild weight loss, extreme weight loss, or weight gain. Each option adjusts your calorie recommendations to align with your targets, making it easier to stay on track.

Summary of BMR Benefits

Using the BMR Calculator provides several benefits. You gain insights into your body’s caloric needs and can develop a plan to reach your health goals. By understanding your metabolism better, you're equipped to make healthier Food choices and maintain an active lifestyle. Ultimately, the BMR Calculator is your ally in effective weight management.