Bmi Metabolic Rate Calculator

by

BMI & Metabolic Rate Calculator

Male Female
Sedentary (little or no exercise) Lightly active (light exercise/sports 1-3 days/week) Moderately active (moderate exercise/sports 3-5 days/week) Very active (hard exercise/sports 6-7 days a week) Extra active (very hard exercise/sports & physical job or 2x training)
function calculateBmiAndMetabolicRate() { var weight = parseFloat(document.getElementById("weight").value); var height = parseFloat(document.getElementById("height").value); var age = parseFloat(document.getElementById("age").value); var gender = document.getElementById("gender").value; var activityLevel = parseFloat(document.getElementById("activityLevel").value); var resultDiv = document.getElementById("result"); resultDiv.innerHTML = "; // Clear previous results // BMI Calculation var bmi = 0; if (!isNaN(weight) && !isNaN(height) && height > 0) { var heightInMeters = height / 100; bmi = weight / (heightInMeters * heightInMeters); bmi = bmi.toFixed(1); // Round BMI to 1 decimal place } // BMR (Basal Metabolic Rate) Calculation using Mifflin-St Jeor Equation var bmr = 0; if (!isNaN(weight) && !isNaN(height) && !isNaN(age) && age > 0) { if (gender === "male") { bmr = (10 * weight) + (6.25 * height) – (5 * age) + 5; } else { // female bmr = (10 * weight) + (6.25 * height) – (5 * age) – 161; } bmr = bmr.toFixed(0); // Round BMR to nearest whole number } // TDEE (Total Daily Energy Expenditure) Calculation var tdee = 0; if (!isNaN(bmr) && !isNaN(activityLevel)) { tdee = bmr * activityLevel; tdee = tdee.toFixed(0); // Round TDEE to nearest whole number } var bmiCategory = ""; if (!isNaN(bmi)) { if (bmi = 18.5 && bmi = 25 && bmi < 29.9) { bmiCategory = "Overweight"; } else { bmiCategory = "Obesity"; } } if (!isNaN(bmi) && !isNaN(bmr) && !isNaN(tdee)) { resultDiv.innerHTML += "Your BMI is: " + bmi + " (" + bmiCategory + ")"; resultDiv.innerHTML += "Your Basal Metabolic Rate (BMR) is: " + bmr + " calories per day"; resultDiv.innerHTML += "Your Total Daily Energy Expenditure (TDEE) is: " + tdee + " calories per day"; resultDiv.innerHTML += "BMR is the number of calories your body burns at rest. TDEE accounts for your activity level."; } else { resultDiv.innerHTML = "Please enter valid numbers for all fields."; } } #bmiMetabolicRateCalculator { font-family: sans-serif; border: 1px solid #ccc; padding: 20px; border-radius: 8px; max-width: 500px; margin: 20px auto; background-color: #f9f9f9; } #bmiMetabolicRateCalculator h2 { text-align: center; color: #333; margin-bottom: 20px; } .calculator-inputs { display: grid; grid-template-columns: 1fr 1fr; gap: 15px; margin-bottom: 20px; } .input-group { display: flex; flex-direction: column; } .input-group label { margin-bottom: 5px; font-weight: bold; color: #555; } .input-group input[type="number"], .input-group select { padding: 10px; border: 1px solid #ccc; border-radius: 4px; font-size: 1rem; } #bmiMetabolicRateCalculator button { grid-column: 1 / -1; /* Span across all columns */ padding: 12px 20px; background-color: #4CAF50; color: white; border: none; border-radius: 4px; font-size: 1.1rem; cursor: pointer; transition: background-color 0.3s ease; } #bmiMetabolicRateCalculator button:hover { background-color: #45a049; } .calculator-result { margin-top: 20px; padding: 15px; background-color: #e7f3fe; border-left: 6px solid #2196F3; border-radius: 4px; text-align: center; } .calculator-result p { margin-bottom: 10px; color: #333; } .calculator-result strong { color: #007bff; } .calculator-result small { color: #777; font-style: italic; } .calculator-result .error { color: red; font-weight: bold; }

Understanding BMI and Metabolic Rate

Your Body Mass Index (BMI) and Basal Metabolic Rate (BMR) are two fundamental metrics used to assess your general health and energy expenditure. Understanding these numbers can provide valuable insights into your weight status and the amount of energy your body needs to function at rest.

What is BMI?

Body Mass Index (BMI) is a measure that uses your weight and height to estimate the amount of body fat you have. It's a simple screening tool that can help categorize whether your weight falls into a healthy range for your height. A higher BMI generally indicates a higher percentage of body fat, while a lower BMI might suggest being underweight. The formula for BMI is weight in kilograms divided by height in meters squared (kg/m²).

  • Underweight: BMI below 18.5
  • Normal weight: BMI between 18.5 and 24.9
  • Overweight: BMI between 25 and 29.9
  • Obesity: BMI of 30 or greater

It's important to note that BMI doesn't directly measure body fat and doesn't account for muscle mass, bone density, or body composition, so it's not a perfect indicator for everyone, especially athletes or individuals with significant muscle mass.

What is Metabolic Rate?

Metabolic rate refers to the rate at which your body burns calories to perform essential life-sustaining functions. There are two main components to consider:

  • Basal Metabolic Rate (BMR): This is the minimum number of calories your body needs to keep vital functions like breathing, circulation, cell production, and brain activity running while you are at complete rest (e.g., sleeping). Factors influencing BMR include age, gender, weight, height, body composition (muscle vs. fat), and genetics. The Mifflin-St Jeor equation is a commonly used and relatively accurate formula for estimating BMR.
  • Total Daily Energy Expenditure (TDEE): This is the total number of calories you burn in a 24-hour period, including your BMR plus the calories burned through all your daily activities – from digesting food to exercising. TDEE is calculated by multiplying your BMR by an activity factor that represents your typical lifestyle.

Understanding your BMR and TDEE can be crucial for weight management. If you aim to lose weight, you typically need to consume fewer calories than your TDEE. If you aim to gain weight, you need to consume more calories. Maintaining your current weight involves balancing calorie intake with your TDEE.

How to Use This Calculator

Enter your current weight in kilograms (kg), height in centimeters (cm), age in years, select your gender, and choose your typical daily activity level. The calculator will then provide your estimated BMI, BMR, and TDEE. Use these figures as a guide to understand your body's energy needs and current weight status.

Example Calculation:

Let's consider a 30-year-old male who weighs 80 kg and is 180 cm tall. He describes his activity level as moderately active (exercises 3-5 days a week).

  • Weight: 80 kg
  • Height: 180 cm
  • Age: 30 years
  • Gender: Male
  • Activity Level: Moderately active (factor 1.55)

Using the calculator with these inputs:

  • BMI Calculation: 80 / (1.80 * 1.80) ≈ 24.7. This falls into the "Normal weight" category.
  • BMR Calculation (Mifflin-St Jeor for Male): (10 * 80) + (6.25 * 180) – (5 * 30) + 5 = 800 + 1125 – 150 + 5 = 1780 calories.
  • TDEE Calculation: 1780 * 1.55 ≈ 2759 calories.

This means the individual needs approximately 2759 calories per day to maintain his current weight, considering his activity level.

Leave a Comment