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Choose metric (kg and cm) or imperial (pounds, feet and inches).
CALCULATORS · FREE ONLINE TOOL
BMI Calculator
Check your body mass index and healthy weight rangeBody mass index is the number doctors, insurers and fitness apps ask for first, because it needs nothing more than height and weight yet says a lot. This calculator gives your BMI to one decimal place with the WHO category and your healthy weight range.
// BMI CALCULATOR · GET STARTED
Use BMI Calculator
Check your body mass index and healthy weight range
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Enter a weight and height above zero and your BMI will appear here. This calculator is designed for adults.
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How to use the BMI Calculator
Enter weight and height
Enter your weight and your height.
Read your BMI result
Read your BMI, category, healthy weight range and the change needed to reach it.
// BMI CALCULATOR · ABOUT THIS TOOL
About the BMI Calculator
Body mass index is the quick screening number doctors, insurers and fitness apps reach for first. This calculator gives it to one decimal place, in the standard WHO category, plus the healthy weight range for your height.
If you are outside the normal range, it tells you how much weight you would need to gain or lose to reach it. Metric and imperial units both work, all computed in your browser.
Where it helps most
A screening number, computed properly.
Health checkups
Walk into a checkup knowing your number and WHO category before the doctor even asks for it at your next appointment.
Fitness goals
If you fall outside the normal band, it states plainly how much you would need to gain or lose to reach it.
Insurance forms
Forms that ask for BMI get an accurate figure to one decimal place, recalculated monthly instead of a generic chart row guess.
Tracking progress
Recheck monthly and watch the number move as diet and exercise take effect, with a practical target attached that updates every month.
Reading it right
What the number does and does not say.
WHO categories
Underweight below 18.5, normal from 18.5 to 24.9, overweight from 25 to 29.9, and obese at 30 and above, for adults aged 18 and over.
Personalized range
The healthy range is computed from your exact height directly, never pulled from a one size fits all table like generic charts use.
Know the limits
BMI is a screening guide, not a diagnosis: it cannot tell muscle from fat, so athletes can score high while perfectly healthy.
BMI Calculator: private by design
Everything runs in your browser, so no health data is sent anywhere.
BMI Calculator FAQs
BMI is your weight relative to your height. Using metric units, divide your weight in kilograms by your height in metres squared (kg/m2). With imperial units, multiply your weight in pounds by 703, then divide by your height in inches squared.