Check your Body Mass Index by entering your height and weight below — switch between metric and imperial units anytime.
This BMI calculator gives you an instant Body Mass Index reading using either metric (kilograms and centimeters) or imperial (pounds and inches) units. Just enter your height and weight and tap Calculate — no sign-up, no download, and the result appears immediately in your browser.
Body Mass Index (BMI) is a simple screening measurement calculated from your height and weight. It's widely used by doctors and health organizations as a quick way to estimate whether a person's weight falls into a healthy range for their height.
| BMI Range | Category |
|---|---|
| Below 18.5 | Underweight |
| 18.5 – 24.9 | Normal weight |
| 25.0 – 29.9 | Overweight |
| 30.0 and above | Obese |
In metric units, BMI equals your weight in kilograms divided by your height in meters, squared. In imperial units, it's your weight in pounds divided by your height in inches squared, multiplied by 703. This calculator handles the math for you automatically in either unit system.
BMI is a useful general indicator, but it doesn't directly measure body fat and doesn't account for factors like muscle mass, bone density, age, or sex. Athletes or very muscular people may show a higher BMI without carrying excess body fat. Use BMI as a starting point, not a diagnosis, and speak with a healthcare provider for a complete picture of your health.
What is BMI? BMI (Body Mass Index) is a number calculated from your height and weight that estimates whether your weight is in a healthy range for your height.
How is BMI calculated? BMI is calculated as weight in kilograms divided by height in meters squared. This calculator also supports imperial units (pounds and inches).
What are the BMI categories? Under 18.5 is underweight, 18.5 to 24.9 is normal weight, 25 to 29.9 is overweight, and 30 or above is considered obese.
Is BMI accurate for everyone? BMI is a useful general screening tool but does not account for muscle mass, bone density, age, or sex. Athletes and very muscular people may show a higher BMI without excess body fat. Consult a healthcare provider for a full assessment.
Is this BMI calculator free? Yes, it is completely free with no sign-up required, and runs instantly in your browser.
Does it work in both kg and lb? Yes — switch between Metric (kg/cm) and Imperial (lb/in) using the toggle above the form.
Does this store or upload my data? No — the calculation runs entirely in your browser. Nothing is sent to any server.
Medical disclaimer: This tool provides a general estimate only and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider with questions about your health.