BMI Calculator
BMI Calculator: free, accurate and easy to use. Results update instantly in your browser, with no sign-up.
How to use
Body Mass Index (BMI) compares your weight with your height to give a quick screening category: underweight, normal weight, overweight or obese. Enter your weight and height in metric or imperial units. BMI is a general screening tool and does not measure body fat or consider age, muscle mass or health conditions.
- Enter your numbers.
- Results update instantly as you type.
- Adjust the values to compare scenarios.
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Frequently asked questions
How is BMI calculated?
BMI = weight in kilograms ÷ height in metres squared.
What is a healthy BMI?
For most adults, the World Health Organization classes a BMI from 18.5 to 24.9 as normal weight. Speak to a doctor for personal advice.
Is it free?
Yes. All calculators are free, with no sign-up and no limits.
Is my data stored?
No. Calculations run in your browser and nothing you enter is sent or stored.
How accurate are the results?
Calculations use standard formulas. Results are estimates for general information; for important decisions, confirm with a professional or your provider.