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Mycelgrid
BMI Calculator

About this app

About BMI Calculator

BMI Calculator is a free, adult-only height-and-weight calculation published by Mycelgrid LLC. It displays a rounded BMI and the matching CDC adult screening category for ages 20 or older.

How the result is calculated

BMI = kilograms divided by meters squared. U.S. units use exact standard conversions: 1 lb = 0.45359237 kg and 1 in = 0.0254 m. Internal rational comparisons use full precision for the CDC adult categories, then present BMI to one decimal. An adjacent note explains threshold-crossing rounding.

Browser-local measurement handling

Height, weight and current results are processed in the active browser page without a Mycelgrid calculation server, database, account or app-owned stored history. Leaving or reloading the page discards those values. Copy, CSV and Print can create deliberate copies on the user's device. The interactive BMI page is excluded from Mycelgrid’s third-party advertising scripts and site analytics scripts.

What BMI cannot determine

It does not directly measure body composition or diagnose disease and does not provide advice about treatment, lifestyle or a medically appropriate weight. The adult thresholds are not intended to interpret BMI for ages 2–19, and BMI from current weight does not assess pregnancy weight gain. Inputs and their measurement accuracy affect the output.

Government references

CDC adult BMI screening categories; CDC About BMI; CDC Adult BMI Calculator; CDC Child and Teen BMI Calculator; CDC pregnancy guidance; NIST measurement units and NIST Handbook 44 unit definitions. These are external informational sources; Mycelgrid is not affiliated with, sponsored or endorsed by the CDC or NIST.

Platform privacy and legal terms

For technical site processing, third-party services elsewhere on the site, and applicable non-advice limitations, consult Mycelgrid Privacy Policy and Mycelgrid Terms of Use. This app is not a medical device or a substitute for professional evaluation.

Privacy, data and limits

BMI Calculator calculates the height-and-weight result in this browser page. The calculator does not submit entered heights, weights or BMI results to Mycelgrid for the calculation, and does not maintain a personal calculation history, account or cloud recovery. Leaving or reloading the page can discard work. Copy, CSV and Print / Save PDF may place the entered values and BMI results into the clipboard, local files or print output when you explicitly choose those actions. This is educational screening information for adults age 20 and older, not medical advice, medical testing, diagnosis, treatment or proof of an individual's health. The CDC adult ranges use unrounded BMI; the displayed value is rounded to one decimal, and inputs and measurement accuracy affect the result. Children and teens require percentile-based assessment. During pregnancy, current-weight BMI does not determine recommended weight gain. Mycelgrid LLC is not affiliated with, sponsored by or endorsed by the CDC or NIST. For site-level practices, consult Mycelgrid's Privacy Policy and Terms of Use.

The interactive BMI calculator root does not load the site’s advertising or analytics JavaScript. Share App provides only the canonical app URL, not entered values or BMI results.

For platform-wide practices, read the Mycelgrid Privacy Policy and Terms of Use. For a real product problem or accessibility issue, use Contact Mycelgrid.