BMI Calculator
Calculate your Body Mass Index and find your weight category.
How to Use the BMI Calculator
Body Mass Index (BMI) is a simple measure that uses your weight and height to estimate whether you are underweight, normal weight, overweight, or obese. It is widely used by healthcare professionals as a quick screening tool.
- Choose your unit system — switch between Metric (kg and cm) or Imperial (lbs, feet and inches).
- Enter your weight — type your weight in the selected unit.
- Enter your height — provide your height in centimetres or feet and inches.
- Click Calculate BMI — your BMI value and weight category appear instantly.
BMI Categories
- Underweight — BMI below 18.5
- Normal weight — BMI 18.5 to 24.9
- Overweight — BMI 25 to 29.9
- Obese — BMI 30 or above
The formula is BMI = weight (kg) / height (m)². All calculations happen in your browser — no data is sent to any server.
Frequently Asked Questions
What is BMI?
BMI stands for Body Mass Index. It is a numerical value calculated from your weight and height that provides a general indication of whether your body weight falls within a healthy range.
How accurate is BMI?
BMI is a useful screening tool but does not directly measure body fat. It may overestimate body fat in athletes and muscular individuals and underestimate it in older adults. Consult a healthcare provider for a comprehensive assessment.
What is a healthy BMI range?
A BMI between 18.5 and 24.9 is generally considered normal weight. However, the ideal range can vary based on age, sex, ethnicity, and muscle mass.
Does this calculator work for children?
This calculator is designed for adults aged 20 and older. BMI for children and teens uses age- and sex-specific percentiles and requires a different calculation.
Is my data stored or sent anywhere?
No. All calculations run entirely in your browser using JavaScript. Your weight and height are never sent to a server or stored anywhere.
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