Your Basal Metabolic Rate (BMR) is the number of calories your body needs to perform basic life-sustaining functions, such as breathing, circulating blood, and cell production, while at rest. This calculator helps you estimate your BMR based on your age, sex, weight, and height. It's important to note that this is an estimate, and individual metabolic rates can vary.
Male
Female
Understanding Basal Metabolic Rate (BMR)
The BMR is a foundational metric for understanding your daily caloric needs. It represents the energy your body expends when it's completely at rest, equivalent to being in a fasted state and in a thermoneutral environment. Factors influencing BMR include:
Age: BMR generally decreases with age.
Sex: Men typically have a higher BMR than women due to differences in body composition (more muscle mass).
Body Composition: Muscle tissue burns more calories at rest than fat tissue.
Body Size and Shape: Larger individuals generally have a higher BMR.
Genetics: Individual genetic makeup plays a role.
The most common formulas used to estimate BMR are the Harris-Benedict Equation (revised) and the Mifflin-St Jeor Equation. This calculator uses the Mifflin-St Jeor Equation, which is generally considered more accurate for most people.
Mifflin-St Jeor Equation:
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
Once you have your BMR, you can estimate your Total Daily Energy Expenditure (TDEE) by multiplying your BMR by an activity factor. This calculator focuses solely on estimating your BMR.
function calculateBMR() {
var age = parseFloat(document.getElementById("age").value);
var sex = document.getElementById("sex").value;
var weight = parseFloat(document.getElementById("weight").value);
var height = parseFloat(document.getElementById("height").value);
var bmrResultElement = document.getElementById("bmr-result");
bmrResultElement.innerHTML = ""; // Clear previous results
if (isNaN(age) || isNaN(weight) || isNaN(height) || age <= 0 || weight <= 0 || height <= 0) {
bmrResultElement.innerHTML = "Please enter valid positive numbers for age, weight, and height.";
return;
}
var bmr = 0;
if (sex === "male") {
bmr = (10 * weight) + (6.25 * height) – (5 * age) + 5;
} else { // female
bmr = (10 * weight) + (6.25 * height) – (5 * age) – 161;
}
bmrResultElement.innerHTML = "