Based on your activity level, here is your estimated daily calorie burn (TDEE):
Activity Level
Daily Calories
Understanding Your Resting Calorie Rate
The Resting Metabolic Rate (RMR) represents the number of calories your body burns while at complete rest. Even when you are sleeping or sitting still, your body requires energy to maintain basic vital functions such as breathing, circulating blood, controlling body temperature, and cell growth.
Knowing your RMR is the foundational step in creating a nutrition plan. If you eat below your RMR for extended periods, your body may slow down its metabolism to conserve energy. Conversely, knowing your RMR helps you calculate your Total Daily Energy Expenditure (TDEE) to manage weight effectively.
How the Calculator Works
This calculator uses the Mifflin-St Jeor equation, widely considered one of the most accurate formulas for estimating caloric needs in healthy individuals. The formula adjusts for gender, weight, height, and age:
Men: (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) + 5
Women: (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) – 161
RMR vs. BMR
You may often hear RMR used interchangeably with BMR (Basal Metabolic Rate). While very similar, there is a technical difference:
BMR is measured under very strict conditions: immediately upon waking, after a fast, and in a darkened room. It is the absolute minimum energy required for survival.
RMR is measured under less strict conditions and typically includes the energy burn from low-effort bodily processes like eating and short movements. RMR is usually about 10% higher than BMR and is more practical for real-world diet planning.
Factors That Influence Resting Calories
Several variables impact how many calories you burn at rest:
Muscle Mass: Muscle tissue burns more calories at rest than fat tissue. Increasing muscle mass through strength training is one of the best ways to increase your RMR.
Age: Metabolism naturally slows down as we age, primarily due to a loss of muscle mass and hormonal changes.
Body Size: Larger individuals (both in height and weight) have more mass to support and therefore have higher RMRs.
Genetics: Some people naturally have a faster or slower metabolic rate than others.
var currentUnit = 'metric';
function switchUnit(unit) {
currentUnit = unit;
// Toggle buttons
var btnMetric = document.getElementById('btnMetric');
var btnImperial = document.getElementById('btnImperial');
if (unit === 'metric') {
btnMetric.classList.add('active');
btnImperial.classList.remove('active');
document.getElementById('metricHeightInput').classList.remove('hidden');
document.getElementById('imperialHeightInput').classList.add('hidden');
document.getElementById('metricWeightInput').classList.remove('hidden');
document.getElementById('imperialWeightInput').classList.add('hidden');
} else {
btnMetric.classList.remove('active');
btnImperial.classList.add('active');
document.getElementById('metricHeightInput').classList.add('hidden');
document.getElementById('imperialHeightInput').classList.remove('hidden');
document.getElementById('metricWeightInput').classList.add('hidden');
document.getElementById('imperialWeightInput').classList.remove('hidden');
}
}
function calculateRMR() {
// 1. Get Inputs
var age = parseFloat(document.getElementById('age').value);
var gender = document.querySelector('input[name="gender"]:checked').value;
var weightKg = 0;
var heightCm = 0;
// 2. Validate and Convert Units
if (isNaN(age) || age < 1) {
alert("Please enter a valid age.");
return;
}
if (currentUnit === 'metric') {
weightKg = parseFloat(document.getElementById('weightKg').value);
heightCm = parseFloat(document.getElementById('heightCm').value);
if (isNaN(weightKg) || isNaN(heightCm)) {
alert("Please enter valid metric height and weight.");
return;
}
} else {
var weightLbs = parseFloat(document.getElementById('weightLbs').value);
var heightFt = parseFloat(document.getElementById('heightFt').value);
var heightIn = parseFloat(document.getElementById('heightIn').value);
// Handle empty inches as 0 if feet is provided
if (isNaN(heightIn)) heightIn = 0;
if (isNaN(weightLbs) || isNaN(heightFt)) {
alert("Please enter valid imperial height and weight.");
return;
}
// Conversion
weightKg = weightLbs * 0.453592;
heightCm = (heightFt * 30.48) + (heightIn * 2.54);
}
// 3. Calculate RMR (Mifflin-St Jeor)
var rmr = 0;
// Formula: (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) + s
// s is +5 for males and -161 for females
var baseCalc = (10 * weightKg) + (6.25 * heightCm) – (5 * age);
if (gender === 'male') {
rmr = baseCalc + 5;
} else {
rmr = baseCalc – 161;
}
// Round to integer
rmr = Math.round(rmr);
// 4. Display Result
var resultArea = document.getElementById('results-area');
var rmrValueDisplay = document.getElementById('rmrValue');
var tableBody = document.getElementById('activityTableBody');
rmrValueDisplay.innerHTML = rmr.toLocaleString();
resultArea.style.display = "block";
// 5. Calculate Activity Levels (TDEE Multipliers)
var activities = [
{ level: "Sedentary (Little to no exercise)", multiplier: 1.2 },
{ level: "Lightly Active (Exercise 1-3 days/week)", multiplier: 1.375 },
{ level: "Moderately Active (Exercise 3-5 days/week)", multiplier: 1.55 },
{ level: "Very Active (Exercise 6-7 days/week)", multiplier: 1.725 },
{ level: "Extra Active (Physical job or 2x training)", multiplier: 1.9 }
];
var tableHTML = "";
for (var i = 0; i < activities.length; i++) {
var tdee = Math.round(rmr * activities[i].multiplier);
tableHTML += "