Resting Rate Calorie Burn Calculator

Resting Metabolic Rate (BMR) Calculator

Male Female

Your Daily BMR Result

Calories per day (at complete rest)

What is Your Resting Calorie Burn (BMR)?

Your Basal Metabolic Rate (BMR) represents the minimum number of calories your body needs to function while at complete rest. This includes vital processes like breathing, blood circulation, cell production, and brain function. Even if you were to stay in bed all day, your body would still burn these calories to sustain life.

How the Calculation Works

This calculator utilizes the Mifflin-St Jeor Equation, which is currently considered the most accurate formula for predicting resting energy expenditure in healthy adults. The formula factors in your biological sex, weight, height, and age to estimate metabolic activity.

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

Factors Influencing Your Resting Rate

Several variables determine how many calories you burn while sitting still:

• Muscle Mass: Muscle tissue is more metabolically active than fat. People with more lean muscle generally have a higher BMR.
• Age: As we age, muscle mass tends to decrease and metabolic processes slow down, leading to a lower BMR.
• Genetics: Some individuals naturally have a faster or slower metabolism due to hereditary factors.
• Hormones: Thyroid function and other hormonal balances significantly impact how the body burns energy.

How to Use This Information

Knowing your BMR is the foundation of any weight management plan. If you want to lose weight, you must consume fewer calories than your Total Daily Energy Expenditure (TDEE), which is your BMR plus your daily activity. If you want to gain weight, you must eat more than your TDEE. Most experts suggest never consuming fewer calories than your BMR without medical supervision, as this can lead to metabolic adaptation and nutrient deficiencies.

function calculateBMR() { var gender = document.getElementById("gender").value; var age = parseFloat(document.getElementById("age").value); var weight = parseFloat(document.getElementById("weight").value); var height = parseFloat(document.getElementById("height").value); var resultBox = document.getElementById("bmr-result-box"); var output = document.getElementById("bmr-output"); if (isNaN(age) || isNaN(weight) || isNaN(height) || age <= 0 || weight <= 0 || height <= 0) { alert("Please enter valid positive numbers for age, weight, and height."); return; } var bmr = 0; if (gender === "male") { // Mifflin-St Jeor for Men bmr = (10 * weight) + (6.25 * height) – (5 * age) + 5; } else { // Mifflin-St Jeor for Women bmr = (10 * weight) + (6.25 * height) – (5 * age) – 161; } output.innerText = Math.round(bmr).toLocaleString() + " kcal"; resultBox.style.display = "block"; // Smooth scroll to result resultBox.scrollIntoView({ behavior: 'smooth', block: 'nearest' }); }