BMR Calculator

- May 09, 2025
| |

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 tool designed to help you determine your Basal Metabolic Rate (BMR). BMR is the number of calories your body needs to function while at rest. Knowing your BMR can give you insights into how many calories you need daily, whether your goal is to maintain, lose, or gain weight. This calculator takes into account various personal factors, including your age, gender, weight, height, and activity level to provide accurate results.

How to Use BMR Calculator

Using the BMR Calculator is straightforward. You start by entering personal details like your age, weight, height, and gender. Then, you choose your preferred calculation method: Mifflin-St Jeor, Harris-Benedict, or Katch-McArdle. After that, you can select your activity level and weight goal. The calculator will do the rest, giving you a clear view of your BMR and daily calorie needs.

Choosing the Right Formula

There are several methods to calculate BMR, and the BMR Calculator lets you choose the one that suits you best. Here’s a quick overview of the formulas:

  • Mifflin-St Jeor: Often regarded as the most accurate method.
  • Harris-Benedict: A classic equation that’s still in use today.
  • Katch-McArdle: Ideal for those who know their body fat percentage.

Factors Influencing BMR

Several factors can affect your BMR. Here are some key elements to consider:

  • Age: As you age, your BMR tends to decrease.
  • Gender: Generally, men have a higher BMR than women.
  • Body Composition: More muscle mass can increase your BMR.

Tracking Your Daily Energy Needs

Once you know your BMR, you can easily calculate your Total Daily Energy Expenditure (TDEE). This value tells you how many calories you burn each day when accounting for your activity level. Adjusting your calorie intake based on this number can help in managing your weight effectively.

Setting Your Weight Goals

The BMR Calculator also allows you to set specific weight goals. Whether you're looking to maintain, lose, or gain weight, you can select your target. The results will show you how many calories you need to consume daily to reach your goal safely and sustainably.

Visualising Macronutrient Breakdown

Understanding the macronutrient breakdown is crucial for a balanced diet. The BMR Calculator provides recommendations on how to divide your daily calorie intake among proteins, carbohydrates, and fats. This can help you create a more tailored meal plan, ensuring you meet your nutritional needs effectively.

Why BMR Matters for Your Health

Understanding your BMR is beneficial for your overall health. It helps you manage your weight more effectively and can guide you in making better dietary choices. With the right tools and knowledge, you can take control of your health and well-being.