Privacy policy

The short version: no accounts, no advertising cookies, and nothing you type into a calculator ever leaves your browser.

Last updated 12 September 2026.

What happens in the calculators

All calculations run entirely in your browser. The measurements you enter are not sent to us or to anyone else.

What we collect

Aggregate analytics. We use Cloudflare Web Analytics, which counts visits and pages without cookies and without building profiles of individual visitors.

Usage events. When you press Calculate, the site records that a calculation happened on that page, with a timestamp. No inputs, no results and no identifying details are included. These records are kept for up to 60 days and only tell us which tools earn their keep.

Feedback. If you use the feedback buttons or write a comment, we store the vote, the comment text and the page, for up to a year. Please do not put personal information in feedback comments.

Contact messages. If you use the contact form, we store what you send, including your name and email if you choose to give them, for up to two years, and use it only to read and answer your message.

Where it lives

The site and the small amount of data above are hosted on Cloudflare's infrastructure. We do not sell or share any of it, and there is nothing to sell: we cannot identify you from what we hold.

Advertising

SewCalc currently shows no advertising. If that ever changes, this policy will be updated first and any advertising will comply with the ad network's disclosure requirements.

Your choices

To have a contact message or feedback comment deleted, write to us via the contact page describing roughly when it was sent and we will remove it.