BMI Calculator
Work out your body mass index from height and weight in either metric or imperial units, and see which World Health Organization category the result falls into.
How to use the BMI Calculator
- Choose metric (cm/kg) or imperial (ft-in/lbs).
- Enter your height and your weight.
- Read your BMI value, its category, and the weight range that would put you in the healthy band for your height.
About the BMI Calculator
BMI is weight in kilograms divided by height in metres squared. It is a quick screening number, not a diagnosis: it does not distinguish muscle from fat, and it reads high for very muscular people and low for older adults who have lost muscle. Use it as a rough starting point and talk to a doctor before changing anything about how you eat or train. This tool runs entirely in your browser and stores nothing.
Please note: this is a general wellness estimator, not a medical assessment. It does not diagnose, treat or prevent any condition, and measures like BMI are known to misclassify athletes, older adults and pregnant women. Speak to a qualified clinician about any health concern. Full disclaimer.
Frequently asked questions
What is a healthy BMI range?
The World Health Organization treats 18.5 to 24.9 as the healthy range, under 18.5 as underweight, 25 to 29.9 as overweight and 30 or above as obese.
Is BMI accurate for everyone?
No. BMI does not measure body composition, so athletes with high muscle mass often score as overweight, and it is interpreted differently for children, pregnant women and some ethnic groups.
Can I use pounds and feet instead of kg and cm?
Yes, switch the unit toggle to imperial and enter feet, inches and pounds — the conversion is done for you.
What BMI counts as obesity?
On the World Health Organization scale, 30 and above is classed as obesity, 25 to 29.9 as overweight and 18.5 to 24.9 as the healthy range. BMI ignores muscle mass, so a very muscular build can read high without excess fat.
Related free tools
- GPA / CGPA Calculator — Semester GPA on the 4.0 scale — and your updated CGPA.
- Body Fat Calculator — US Navy body fat percentage from simple tape measurements.
- Electricity Bill Calculator — Appliance-by-appliance energy use and what it costs you.
- Age Calculator — Exact age in years, months, days — plus next birthday.
- Percentage Calculator — What is X% of Y, percent change and more.
- Date Difference — Days, weeks and working days between two dates.
Runs entirely in your browser — nothing you enter is uploaded. Last reviewed and updated .