Personal Metabolic Rate Calculator

Personal Metabolic Rate Calculator

Sedentary (Little or no exercise) Lightly Active (Exercise 1-3 days/week) Moderately Active (Exercise 3-5 days/week) Very Active (Hard exercise 6-7 days/week) Extra Active (Physical job or 2x training)

Your Results

Basal Metabolic Rate (BMR): 0 kcal/day

Total Daily Energy Expenditure (TDEE): 0 kcal/day

*These figures represent the calories your body burns to maintain its current weight.

function calculateMetabolism() { var gender = document.getElementById('pmr_gender').value; var age = parseFloat(document.getElementById('pmr_age').value); var weight = parseFloat(document.getElementById('pmr_weight').value); var height = parseFloat(document.getElementById('pmr_height').value); var activity = parseFloat(document.getElementById('pmr_activity').value); var bmr = 0; if (isNaN(age) || isNaN(weight) || isNaN(height)) { alert("Please enter valid numerical values for Age, Weight, and Height."); return; } // Mifflin-St Jeor Equation if (gender === 'male') { bmr = (10 * weight) + (6.25 * height) – (5 * age) + 5; } else { bmr = (10 * weight) + (6.25 * height) – (5 * age) – 161; } var tdee = bmr * activity; document.getElementById('res_bmr').innerText = Math.round(bmr).toLocaleString() + " kcal/day"; document.getElementById('res_tdee').innerText = Math.round(tdee).toLocaleString() + " kcal/day"; document.getElementById('pmr_results').style.display = 'block'; }

Understanding Your Metabolic Rate

Knowing your metabolic rate is the cornerstone of any successful health, fitness, or weight management plan. This calculator uses the Mifflin-St Jeor Equation, widely considered by nutritionists and clinical dietitians to be the most accurate standard for predicting energy expenditure.

What is BMR (Basal Metabolic Rate)?

Your BMR is the minimum number of calories your body requires to function while at rest. Even if you spent the entire day in bed, your body would still burn these calories to keep your heart beating, lungs breathing, and organs functioning. BMR accounts for approximately 60-75% of your total daily energy expenditure.

What is TDEE (Total Daily Energy Expenditure)?

TDEE is the total number of calories you burn in a 24-hour period, accounting for your BMR plus physical activity, exercise, and the thermic effect of food (digestion). This is the "maintenance" number:

• To Lose Weight: Consume fewer calories than your TDEE (Caloric Deficit).
• To Gain Weight: Consume more calories than your TDEE (Caloric Surplus).
• To Maintain Weight: Consume calories equal to your TDEE.

Metabolic Rate Example

Consider a 35-year-old male who weighs 85kg and is 180cm tall.
1. BMR Calculation: (10 × 85) + (6.25 × 180) – (5 × 35) + 5 = 1,805 kcal/day.
2. Activity Factor: If he is "Moderately Active" (1.55 multiplier).
3. Final TDEE: 1,805 × 1.55 = 2,798 kcal/day.

Factors Influencing Metabolism

While this calculator provides a highly accurate estimate, several factors can influence your specific metabolic rate:

• Muscle Mass: Muscle tissue is more metabolically active than fat tissue. People with more muscle burn more calories at rest.
• Hormones: Thyroid function and other hormonal balances play a significant role in metabolic speed.
• Dietary Choices: Protein has a higher thermic effect than fats or carbohydrates, meaning your body burns more energy digesting it.
• Sleep Quality: Lack of sleep can slow down metabolism and increase hunger-regulating hormones.