Omni Calculator Basal Metabolic Rate

Basal Metabolic Rate (BMR) Calculator

Estimate your body's energy needs at rest using the Mifflin-St Jeor Equation.

Male Female

Your Basal Metabolic Rate is:

0

Calories / Day

Total Daily Energy Expenditure (TDEE)

Sedentary (little or no exercise)	0 cal
Lightly Active (1-3 days/week)	0 cal
Moderately Active (3-5 days/week)	0 cal
Very Active (6-7 days/week)	0 cal
Extra Active (Physical job + training)	0 cal

Understanding Your Basal Metabolic Rate (BMR)

Your Basal Metabolic Rate (BMR) represents the minimum number of calories your body needs to function while at complete rest. This energy is used to maintain vital physiological processes such as breathing, blood circulation, cell production, and temperature regulation.

How the BMR Calculation Works

This calculator uses the Mifflin-St Jeor Equation, which is currently considered the most accurate formula for estimating BMR in the general population. The formula differs slightly between biological males and females:

• 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

BMR vs. TDEE

While BMR is your "baseline" energy expenditure, your Total Daily Energy Expenditure (TDEE) is the actual number of calories you burn throughout the day including movement and exercise. To find your TDEE, we multiply your BMR by an activity factor:

• Sedentary: BMR x 1.2
• Lightly Active: BMR x 1.375
• Moderately Active: BMR x 1.55
• Very Active: BMR x 1.725
• Extra Active: BMR x 1.9

Example Calculation

Imagine a 30-year-old male who weighs 80kg and is 180cm tall:

1. (10 × 80) = 800
2. (6.25 × 180) = 1125
3. (5 × 30) = 150
4. BMR = 800 + 1125 – 150 + 5 = 1,780 calories/day.

If this person is moderately active, his TDEE would be roughly 2,759 calories per day (1,780 x 1.55).

Factors that Influence BMR

Several factors can increase or decrease your metabolic rate:

• Muscle Mass: Muscle tissue burns more calories than fat tissue, even at rest.
• Body Size: Larger bodies generally have higher BMRs because they have more tissue to maintain.
• Genetics: Some individuals naturally have a faster or slower metabolism due to inherited traits.
• Hormones: Thyroid hormones significantly impact metabolic speed.
• Environment: Extreme cold or heat can force the body to work harder to maintain core temperature.

function calculateBMR() { var gender = document.getElementById("bmr_gender").value; var age = parseFloat(document.getElementById("bmr_age").value); var weight = parseFloat(document.getElementById("bmr_weight").value); var height = parseFloat(document.getElementById("bmr_height").value); if (isNaN(age) || isNaN(weight) || isNaN(height) || age <= 0 || weight <= 0 || height <= 0) { alert("Please enter valid positive numbers for all fields."); 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; } var roundedBMR = Math.round(bmr); // Display BMR document.getElementById("bmr_value").innerHTML = roundedBMR.toLocaleString(); document.getElementById("bmr_result_box").style.display = "block"; // Calculate TDEE variations document.getElementById("tdee_sedentary").innerHTML = Math.round(roundedBMR * 1.2).toLocaleString() + " cal"; document.getElementById("tdee_light").innerHTML = Math.round(roundedBMR * 1.375).toLocaleString() + " cal"; document.getElementById("tdee_moderate").innerHTML = Math.round(roundedBMR * 1.55).toLocaleString() + " cal"; document.getElementById("tdee_active").innerHTML = Math.round(roundedBMR * 1.725).toLocaleString() + " cal"; document.getElementById("tdee_extra").innerHTML = Math.round(roundedBMR * 1.9).toLocaleString() + " cal"; document.getElementById("tdee_table").style.display = "block"; // Smooth scroll to result document.getElementById("bmr_result_box").scrollIntoView({ behavior: 'smooth', block: 'nearest' }); }