BMI Calculator
Calculate BMI from metric height and weight.
Last updated: October 15, 2026
Your BMI
0.0
- Category: —
On this page
Quick summary: Calculate BMI from metric height and weight.
Read the complete guide
Updated reference sections in this guide are in English.
Guide language: English. Updated October 15, 2026.
What this calculator does
Calculate BMI from kilograms and centimeters. The displayed categories are for adults aged 20 or older.
How to use the calculator
Use the inputs and units named in this form. Select Calculate after changing the values.
How the calculation works
BMI = weight in kilograms / (height in meters squared). The height field expects centimeters, so the tool divides that input by 100 before squaring it. The result is displayed to one decimal place; the category uses the value before rounding.
Worked example
For 70 kg and 175 cm, height is 1.75 m. BMI is 70 / (1.75 x 1.75) = 22.8571, displayed as 22.9. Entering 1.75 in the centimeter field would represent a height of 1.75 cm, not 1.75 m.
How to interpret the result
Compare the result with the assumptions and units shown above. The calculation uses the values entered into this page.
Assumptions and limitations
CDC adult categories are below 18.5: underweight; 18.5 to below 25: healthy weight; 25 to below 30: overweight; and 30 or higher: obesity. BMI is a screening measure, interpreted with other health information. Child and teen BMI uses a different assessment, which this form does not calculate.
Common mistakes
Check the units and time period before calculating. An error message means the result cannot be calculated from the current inputs.
Privacy
The calculation runs in your browser. This form needs the numerical inputs shown, not names, account numbers or passwords.
Frequently asked questions
Can I enter pounds and inches?
Convert them to kilograms and centimeters first; the current form has no imperial-unit selector.
Why can the rounded result look like a different category?
Classification uses the unrounded BMI. A value just below a boundary can round to that boundary.
Does BMI alone diagnose a condition?
No. The result is a screening measure and does not determine a diagnosis or treatment.