Calculations stay in the browser
The calculator performs its arithmetic on your device. The site does not send your input measurements or calculated results to an application database. Temporary inputs are shared between tools during your open visit so you do not need to enter them again.
Saving is optional
We write measurement history to browser local storage only after you select Save or confirm an import. Anyone who can use that browser profile may be able to read it. Local storage is not an encrypted medical record. Private browsing or clearing site data can remove saved history.
Export, import, and delete
Use My measurements to export JSON for backup or CSV for a spreadsheet. Imports are read locally, checked against the stored formulas, and shown for confirmation. Exported files contain personal inputs and results. Keep them somewhere appropriate. You can remove individual results or clear all stored history.
Hosting and external links
ChatGPT Sites serves the website and may process ordinary connection information under its platform policies. Optional Google Analytics starts only when you allow it in the footer. It uses cookies and sends Google the public page path and ordinary device and connection information. Page addresses exclude query strings and fragments. Calculator inputs, results, and saved history are excluded. Advertising features and automatic enhanced measurement are disabled. Use the footer control to turn analytics off and remove its cookies. We do not add session replay or photo processing. Source links open third-party sites with their own policies. Download and print actions stay local until you choose to send a file elsewhere.
Limits of this release
There is no cloud synchronization, account recovery, or automatic backup. Public pages contain educational information, not your personal records. We keep measurements out of public URLs, metadata, and search indexes.
Updated September 12, 2026.