What is a BMI Calculator?
Body Mass Index (BMI) is a simple calculation using a person's height and weight. The formula is BMI = kg/m², where kg is a person's weight in kilograms and m² is their height in metres squared. Our free BMI calculator gives you an instant health assessment based on the WHO (World Health Organization) classification.
⚡ Key Features & Benefits
💯 100% Free — No registration, no login, unlimited checks.
🏥 WHO Standards — Results based on World Health Organization BMI categories.
⚡ Instant Results — Get your BMI score and category immediately.
🔒 Private — Your health data never leaves your browser.
📋 Step-by-Step Usage Guide
- Enter Weight — Input your weight in kilograms.
- Enter Height — Input your height in centimeters.
- Click Calculate — Instantly see your BMI score and health category.
📊 BMI Categories (WHO)
| BMI Range | Category | Health Risk |
|---|---|---|
| Below 18.5 | Underweight | Potential malnutrition |
| 18.5 – 24.9 | Normal weight | Lowest risk |
| 25.0 – 29.9 | Overweight | Increased risk |
| 30.0 and above | Obese | High risk |
🧮 How to Calculate BMI Manually?
If you want to calculate your BMI without a tool, you can use the standard Metric formula:
BMI = Weight (kg) / [Height (m) × Height (m)]
Example: If your weight is 70kg and your height is 1.75m (175cm), the calculation would be:
70 / (1.75 * 1.75) = 22.86. Your BMI is 22.9, which falls into the Normal category.
❓ Frequently Asked Questions
BMI is a useful screening tool, but it doesn't directly measure body fat. Athletes with high muscle mass may have a high BMI but low body fat. Always consult a healthcare professional for a complete assessment.
According to the WHO, a healthy BMI is between 18.5 and 24.9. This range is associated with the lowest risk of weight-related health problems.
No. All calculations happen entirely in your browser. We never collect, store, or transmit any of your personal health information.