BMI Calculator
Calculate your Body Mass Index (BMI) instantly. Find out if your weight is in a healthy range and get personalized recommendations.
Unit System
Your Measurements
Your Results
Enter your weight and height, then click Calculate to see your BMI
Instant Results
Get your BMI calculated in real-time. No waiting, no page reloads.
WHO Standards
Based on World Health Organization BMI classification. Supports both metric and imperial units.
100% Private
All calculations happen in your browser. Your data is never sent to any server.
How to Use the BMI Calculator
Choose your preferred unit system: Metric (kilograms and centimeters) or Imperial (pounds, feet, and inches).
Enter your weight. For metric, use kilograms. For imperial, use pounds.
Enter your height. For metric, use centimeters. For imperial, enter feet and inches separately.
Click Calculate BMI to instantly see your BMI value, category, and healthy weight range for your height.
Why Use Our BMI Calculator
WHO Classification
Uses the official World Health Organization BMI categories: Underweight (below 18.5), Normal (18.5-24.9), Overweight (25-29.9), and Obese (30+) with sub-classes.
Dual Unit Support
Switch between metric (kg/cm) and imperial (lbs/ft+in) with one click. The calculator converts automatically so you can use whichever system you prefer.
Healthy Weight Range
See the healthy weight range for your specific height based on a BMI of 18.5 to 24.9, helping you set realistic and evidence-based goals.
No Account Required
Use the calculator instantly without signing up. Your measurements stay in your browser and are never stored or shared with anyone.
Frequently Asked Questions
What is BMI?
BMI (Body Mass Index) is a simple measure that uses your height and weight to estimate whether you are underweight, at a healthy weight, overweight, or obese. It is calculated by dividing weight in kilograms by height in meters squared.
What is a healthy BMI range?
According to the World Health Organization, a healthy BMI is between 18.5 and 24.9. Below 18.5 is considered underweight, 25 to 29.9 is overweight, and 30 or above is classified as obese.
Is BMI accurate for everyone?
BMI is a useful screening tool but has limitations. It does not distinguish between muscle and fat, so athletes or very muscular people may have a high BMI despite being healthy. Age, gender, and ethnicity can also affect interpretation.
How often should I check my BMI?
Checking your BMI once every few months is sufficient for most people. If you are actively working on weight management, monthly checks can help track your progress alongside other measurements.
Is this calculator free to use?
Yes, completely free with no limits. All calculations happen in your browser, so your data remains private. No registration or account is required.