Privacy Policy

Effective October 21, 2026.

Calculator inputs

Interactive calculations run in your browser. The worksheets do not send your measurements or rates to a contractor or our contact mailbox. Printing uses your browser's print controls. The tools do not request a phone number or save project inputs to a marketing list.

When browser storage is available, worksheets save your entries on this device so they can be restored after a reload. This includes any quote notes you type. Reset clears the saved entries for that worksheet. You can also remove them by clearing this site's browser data. On a shared device, reset the worksheet when you have finished.

Contact messages

If you submit the editorial contact form, we receive the name, reply email, subject and message you enter. The submission also records its time and request country. We use these details to review and answer the message or investigate a correction.

The form uses a hidden spam field, a signed timing token and request limits. The sending IP address is used for short-lived rate-limit records. The configured submission queue expires undelivered records after 90 days. That queue expiry is not a deletion deadline for messages already delivered to the site's mailbox or records retained to handle a correction.

Hosting and source links

The hosting service processes network requests to serve pages and protect the site. This can include an IP address and ordinary request data. Source links take you to independently operated websites with their own policies. Their pages are not loaded as calculator inputs.

Current tracking and commercial status

This site has no advertising, affiliate links or newsletter sign-up. No analytics measurement ID is configured, and analytics and commercial click scripts are omitted. Local site search reads the site's search index. Contact submissions are not added to a newsletter or passed to a contractor matching service.

Questions and requests

Use the contact form to ask about a message or request correction or deletion of information you sent. Include enough detail to identify it without sending unnecessary personal information. If the site's data practices change, this page will be updated with a new effective date.