Body Calculator

Male Female

Sedentary (Little to no exercise) Lightly Active (1-3 days/week) Moderately Active (3-5 days/week) Very Active (6-7 days/week) Extra Active (Physical job + training)

Your Results

Body Mass Index (BMI) –

Basal Metabolic Rate (BMR) – kcal/day

Daily Calorie Needs (TDEE) – Calories/day

This is the energy needed to maintain your current weight based on your activity level.

function calculateBodyMetrics() { var gender = document.getElementById('body_gender').value; var age = parseFloat(document.getElementById('body_age').value); var height = parseFloat(document.getElementById('body_height').value); var weight = parseFloat(document.getElementById('body_weight').value); var activity = parseFloat(document.getElementById('body_activity').value); if (isNaN(age) || isNaN(height) || isNaN(weight) || age <= 0 || height <= 0 || weight <= 0) { alert("Please enter valid positive numbers for age, height, and weight."); return; } // BMI Calculation: Weight (kg) / [Height (m)]^2 var heightM = height / 100; var bmi = weight / (heightM * heightM); // BMR Calculation (Mifflin-St Jeor Equation) var bmr; if (gender === 'male') { bmr = (10 * weight) + (6.25 * height) – (5 * age) + 5; } else { bmr = (10 * weight) + (6.25 * height) – (5 * age) – 161; } // TDEE Calculation var tdee = bmr * activity; // BMI Category var bmiCat = ""; var bmiColor = ""; if (bmi < 18.5) { bmiCat = "Underweight"; bmiColor = "#f1c40f"; } else if (bmi < 25) { bmiCat = "Normal Weight"; bmiColor = "#27ae60"; } else if (bmi < 30) { bmiCat = "Overweight"; bmiColor = "#e67e22"; } else { bmiCat = "Obese"; bmiColor = "#c0392b"; } // Display results document.getElementById('res_bmi').innerText = bmi.toFixed(1); document.getElementById('res_bmi_cat').innerText = bmiCat; document.getElementById('res_bmi_cat').style.color = bmiColor; document.getElementById('res_bmr').innerText = Math.round(bmr).toLocaleString(); document.getElementById('res_tdee').innerText = Math.round(tdee).toLocaleString(); document.getElementById('body_results_box').style.display = 'block'; }

Understanding Your Body Metrics

Using a body calculator is the first step toward achieving your fitness and health goals. Whether you want to lose weight, gain muscle, or maintain your current physique, understanding how your body utilizes energy is crucial.

What is BMI (Body Mass Index)?

BMI is a simple screening tool that uses your height and weight to estimate if you are at a healthy weight. While it does not measure body fat directly, it correlates moderately with more direct measures of body fat. It is a standard metric used by healthcare professionals to categorize weight status into groups like underweight, normal weight, overweight, and obese.

BMR vs. TDEE: What's the Difference?

Two of the most important numbers in nutrition are BMR and TDEE:

• Basal Metabolic Rate (BMR): This is the number of calories your body burns at rest just to keep your organs functioning (breathing, heart rate, cell production). Think of it as the energy you would burn if you stayed in bed all day.
• Total Daily Energy Expenditure (TDEE): This is the total number of calories you burn in a day, including physical activity and the thermic effect of food. This is the real "maintenance" number you need to know.

Realistic Example of Body Calculations

Let's look at a practical scenario for a user:

Example User: 35-year-old Male, 180cm tall, weighing 85kg, Moderately Active.

• BMI: 26.2 (Categorized as Overweight)
• BMR: ~1,855 Calories (Minimum energy for survival)
• TDEE: ~2,875 Calories (Energy needed to stay at 85kg)
• Weight Loss Goal: To lose 0.5kg per week, this user would aim for approximately 2,375 calories daily (a 500-calorie deficit).

How to Use These Results

Once you have your TDEE, you can adjust your caloric intake based on your goals:

1. Weight Loss: Consume 250-500 calories below your TDEE.
2. Muscle Gain: Consume 250-500 calories above your TDEE while performing resistance training.
3. Maintenance: Eat as close to your TDEE as possible.

Note: These calculations are estimates based on standardized formulas. Individual metabolism may vary due to muscle mass, genetics, and health conditions. Always consult with a healthcare provider or nutritionist before starting a new diet or exercise regimen.