⚖️ BMI / BMR Calculator
Calculate your Body Mass Index, Basal Metabolic Rate, and daily recommended calories all at once.
What is BMI?
BMI (Body Mass Index) is calculated by dividing your weight (kg) by the square of your height (m). It's a widely used indicator to estimate body fat levels.
WHO BMI Classification
| Category | BMI Range |
|---|---|
| Underweight | Below 18.5 |
| Normal weight | 18.5 – 24.9 |
| Overweight | 25.0 – 29.9 |
| Obesity Class I | 30.0 – 34.9 |
| Obesity Class II | 35.0 – 39.9 |
| Obesity Class III | 40.0 and above |
What is BMR?
Basal Metabolic Rate (BMR) is the minimum energy your body needs to sustain vital functions. This calculator uses the Harris-Benedict equation:
- Male: 88.362 + (13.397 × weight kg) + (4.799 × height cm) - (5.677 × age)
- Female: 447.593 + (9.247 × weight kg) + (3.098 × height cm) - (4.330 × age)
Daily Calorie Recommendations
Total Daily Energy Expenditure (TDEE) is calculated by multiplying BMR by an activity factor:
- Sedentary (little/no exercise): BMR × 1.2
- Lightly active (1-3 days/week): BMR × 1.375
- Moderately active (3-5 days/week): BMR × 1.55
- Very active (6-7 days/week): BMR × 1.725
- Extra active (athlete level): BMR × 1.9
Frequently Asked Questions
What is a healthy BMI range?
According to the WHO, a healthy BMI is between 18.5 and 24.9. Below 18.5 is considered underweight, and 25.0 or above is classified as overweight. However, BMI does not distinguish between muscle and fat, so athletes may have a high BMI without being overweight.
How accurate is BMI as a health indicator?
BMI is a useful screening tool for general populations but has limitations. It does not account for muscle mass, bone density, age, or body fat distribution. For a more complete health assessment, consider waist circumference, body fat percentage, and other metrics alongside BMI.
What is BMR and why does it matter?
BMR (Basal Metabolic Rate) is the number of calories your body needs at rest to maintain basic functions like breathing and circulation. Knowing your BMR helps estimate daily calorie needs. Multiply BMR by an activity factor (1.2–1.9) to get your Total Daily Energy Expenditure (TDEE).