BMI CalculatorNEW
Check your body mass index in metric or imperial units
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AllFreeTool is a free online BMI calculator that works in both metric and imperial units, so you can enter kilograms and centimetres or pounds and inches. It gives you the body mass index, the weight category that falls into, and the healthy weight range for your height. The calculation happens in your browser and no measurement of you is ever uploaded.
It is a quick general reference for adults who want a rough sense of where their weight sits relative to their height. Remember that BMI is a population-level screening figure rather than a diagnosis, and that it does not apply to athletes, to people who are pregnant, or to children.
Why use BMI Calculator on AllFreeTool?
Two Unit Systems
Enter kilograms and centimetres, or pounds and inches, and the conversion is handled for you.
Weight Category
See the category your index falls into, from underweight through to obese.
Healthy Weight Range
Get the weight range that corresponds to a normal BMI for your height.
Runs Locally
Your weight and height are used on your own device and never leave the browser.
How to use BMI Calculator
Choose Units
Switch between metric and imperial input before entering your measurements.
Enter Measurements
Type your weight and height into the two fields, then press the calculate button.
Read the Result
Review the BMI value, the category it falls into, and the healthy weight range.
Common questions
How is BMI calculated?＋
BMI is your weight in kilograms divided by your height in metres squared. If you enter imperial units, the tool converts pounds and inches to metric first and then applies the same formula, so both entry modes give identical results for the same person.
Is BMI accurate for everyone?＋
No. BMI is a rough screening measure that does not distinguish muscle from fat, so an athlete may appear overweight while carrying very little body fat, and it is not meaningful for children or for anyone who is pregnant. The page also shows the Chinese adult reference bands alongside the international categories.
What does the healthy weight range mean?＋
It is the range of weights that would place you inside the normal category for your height, which is roughly a BMI from 18.5 to 24 under the reference used here. Treat it as a general guide and discuss any concern about your weight with a doctor or dietitian.
Is my weight and height uploaded?＋
No. The arithmetic runs locally in your browser with no network request, so your measurements are never transmitted or written to a database. The tool works offline and the results disappear when you close the page.