Calculator Basal Metabolic Rate

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Basal Metabolic Rate (BMR) Calculator

Male Female
function calculateBMR() { var gender = document.getElementById("gender").value; var weight = parseFloat(document.getElementById("weight").value); var height = parseFloat(document.getElementById("height").value); var age = parseFloat(document.getElementById("age").value); var bmr = 0; if (isNaN(weight) || isNaN(height) || isNaN(age) || weight <= 0 || height <= 0 || age <= 0) { document.getElementById("result").innerHTML = "Please enter valid positive numbers for all fields."; return; } if (gender === "male") { // Mifflin-St Jeor Equation for Men bmr = (10 * weight) + (6.25 * height) – (5 * age) + 5; } else { // Female // Mifflin-St Jeor Equation for Women bmr = (10 * weight) + (6.25 * height) – (5 * age) – 161; } document.getElementById("result").innerHTML = "Your Basal Metabolic Rate (BMR) is: " + bmr.toFixed(2) + " kcal/day"; }

Understanding Your Basal Metabolic Rate (BMR)

Your Basal Metabolic Rate (BMR) is the number of calories your body needs to perform essential life-sustaining functions while at rest. These functions include breathing, circulation, cell production, nutrient processing, protein synthesis, and ion transport. Essentially, it's the energy your body burns just to keep you alive, even if you were to spend the entire day sleeping.

Understanding your BMR is a crucial first step in managing your weight and optimizing your overall health. It forms the baseline for your total daily energy expenditure (TDEE). Your TDEE is your BMR plus the calories you burn through physical activity, the thermic effect of food, and other non-exercise activity thermogenesis (NEAT). By knowing your BMR, you can better estimate how many calories you need to consume to maintain, lose, or gain weight.

Factors Influencing BMR:

  • Body Composition: Muscle tissue burns more calories at rest than fat tissue. Therefore, individuals with more lean muscle mass generally have a higher BMR.
  • Age: BMR typically decreases with age, partly due to a natural decline in muscle mass and metabolic rate.
  • Gender: Men generally have a higher BMR than women, primarily because they tend to have more muscle mass and a larger body size.
  • Genetics: Your inherited genes play a role in determining your metabolic rate.
  • Hormones: Thyroid hormones, in particular, significantly influence metabolism. Imbalances can lead to a higher or lower BMR.
  • Body Size and Shape: Larger individuals generally have higher BMRs due to having more body mass to maintain.

How the BMR Calculator Works:

This calculator uses the widely accepted Mifflin-St Jeor equation, which is considered one of the most accurate formulas for estimating BMR. The equation takes into account your gender, weight, height, and age.

For Men: BMR = (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) + 5

For Women: BMR = (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) – 161

It's important to remember that this is an estimation. Your actual metabolic rate can vary based on the factors mentioned above and other individual physiological differences. For precise dietary and exercise plans, it's always best to consult with a healthcare professional or a registered dietitian.

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