AIAZHHow To Use
- Enter your height in centimeters.
- Enter your weight in kilograms.
- Click "Calculate BMI" to see your Body Mass Index instantly.
- Review your BMI value and the corresponding weight category.
- Use the results to discuss with your healthcare provider.
Frequently Asked Questions
What is BMI and how is it calculated?
BMI (Body Mass Index) is a measure of body fat based on height and weight. It is calculated by dividing weight in kilograms by height in meters squared (kg/m²).
What is a healthy BMI range?
A healthy BMI range is 18.5 to 24.9. Below 18.5 is underweight, 25-29.9 is overweight, and 30 or above is obese. These ranges apply to most adults aged 18-65.
Is BMI accurate for athletes?
BMI may overestimate body fat in athletes and people with high muscle mass since muscle weighs more than fat. For athletes, body fat percentage measurements may be more accurate.
Does BMI apply to children and teenagers?
For children and teens, BMI is interpreted using age and gender-specific percentiles rather than adult categories. Consult a pediatrician for proper assessment.
Is my health data stored or shared?
No. All calculations are performed locally in your browser. Your height, weight, and BMI data never leaves your device.
What are the limitations of BMI?
BMI does not account for muscle mass, bone density, body composition, or fat distribution. It is a screening tool, not a diagnostic measure. Always consult a healthcare professional.
Instant BMI Calculation
Enter your height and weight to get your BMI instantly. The calculation uses the standard WHO formula and runs entirely in your browser.
WHO Classification Standards
Your BMI is classified according to WHO standards: underweight (<18.5), normal (18.5-24.9), overweight (25-29.9), and obese (30+).
100% Private & Secure
Your health data never leaves your device. All calculations happen locally in your browser with JavaScript.
Free & No Signup
No account required, no email needed. Use the BMI calculator unlimited times for free.
Calculate Your BMI Online Free in Seconds
Our free BMI calculator gives you an instant, accurate Body Mass Index measurement. Simply enter your height and weight to determine your BMI category according to WHO standards. The calculation is performed entirely in your browser — no data is uploaded, stored, or shared with any server.
Understanding Your BMI Results
Your BMI result falls into one of four main categories. A normal BMI range (18.5-24.9) is associated with lower health risks for most people. Being underweight or overweight may increase certain health risks. Use your BMI as a starting point for discussions about your health with a medical professional.
BMI vs Body Fat Percentage: What Is the Difference?
While BMI is a useful screening tool, it does not directly measure body fat. Two people with the same BMI can have very different body compositions. For a more complete picture, consider using our Body Fat Calculator alongside the BMI calculator.
How to Maintain a Healthy BMI
Maintaining a healthy BMI involves balanced nutrition, regular physical activity, adequate sleep, and stress management. Small, consistent changes in diet and exercise habits can help you achieve and maintain a healthy weight over time.