Metabolic Resting Rate Calculator Metric

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Resting Metabolic Rate (RMR) Calculator – Metric

Male Female

Your Daily RMR Estimate

Calories per day at complete rest

Total Daily Energy Expenditure (TDEE) Estimates:

function calculateRMR() { var gender = document.getElementById('rmr_gender').value; var age = parseFloat(document.getElementById('rmr_age').value); var weight = parseFloat(document.getElementById('rmr_weight').value); var height = parseFloat(document.getElementById('rmr_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 rmrValue = 0; // Mifflin-St Jeor Equation if (gender === 'male') { rmrValue = (10 * weight) + (6.25 * height) – (5 * age) + 5; } else { rmrValue = (10 * weight) + (6.25 * height) – (5 * age) – 161; } rmrValue = Math.round(rmrValue); document.getElementById('rmr_output').innerHTML = rmrValue + " kcal"; document.getElementById('tdee_sedentary').innerHTML = "Sedentary (no exercise): " + Math.round(rmrValue * 1.2) + " kcal"; document.getElementById('tdee_light').innerHTML = "Lightly Active (1-3 days/week): " + Math.round(rmrValue * 1.375) + " kcal"; document.getElementById('tdee_moderate').innerHTML = "Moderately Active (3-5 days/week): " + Math.round(rmrValue * 1.55) + " kcal"; document.getElementById('tdee_active').innerHTML = "Very Active (6-7 days/week): " + Math.round(rmrValue * 1.725) + " kcal"; document.getElementById('rmr_result_box').style.display = 'block'; }

What is Resting Metabolic Rate (RMR)?

Resting Metabolic Rate (RMR) represents the total number of calories your body burns while at rest. This includes essential physiological functions such as breathing, blood circulation, temperature regulation, and cell production. Unlike Basal Metabolic Rate (BMR), which is measured under strict laboratory conditions, RMR provides a more realistic estimate of energy expenditure for the average person while they are awake but sedentary.

The Mifflin-St Jeor Formula

This metric calculator uses the Mifflin-St Jeor equation, which is widely considered the most accurate formula for estimating metabolic rate in healthy adults. The formula calculates energy requirements based on weight (kg), height (cm), age (years), and biological sex.

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

How to Use RMR for Weight Management

Understanding your RMR is the cornerstone of any nutrition or fitness plan. Your RMR typically accounts for 60-75% of your total daily energy expenditure (TDEE). If you wish to lose weight, you need to create a calorie deficit relative to your TDEE (RMR + physical activity). Conversely, to gain muscle or weight, you must consume more calories than your TDEE.

Realistic Example

Consider a 35-year-old male who weighs 85 kg and is 180 cm tall:

  1. Weight calculation: 10 × 85 = 850
  2. Height calculation: 6.25 × 180 = 1125
  3. Age calculation: 5 × 35 = 175
  4. Final calculation: (850 + 1125 – 175) + 5 = 1,805 calories/day

If this individual has a sedentary job and does not exercise, their TDEE would be roughly 2,166 calories (RMR × 1.2). To lose 0.5 kg per week, they would likely aim for a daily intake of approximately 1,666 calories.

Factors Influencing RMR

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

  • Muscle Mass: Muscle tissue burns more calories at rest than fat tissue. Higher lean mass increases RMR.
  • Genetics: Some individuals naturally have a faster or slower metabolism due to genetic factors.
  • Hormones: Thyroid function and other hormonal balances play a significant role in metabolic speed.
  • Climate: Maintaining body temperature in very cold or very hot environments requires more energy.

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