How this site handles your information, in plain language: almost nothing is collected, and the calculators collect nothing at all.
The calculators run entirely in your browser. Nothing you type into them is sent to us, stored, or shared. The site is hosted on Cloudflare, which processes basic technical data to serve and protect the pages — and that is the extent of the data involved. No analytics is currently installed and no advertising is served. There are no accounts, no newsletters and no sale of personal information — there is no personal information here to sell.
Every calculation on this site — rafter lengths, spans, sizes, angles — is performed locally on your device by the page's own code. Your spans, pitches and measurements never leave the browser, are not transmitted to any server, and are gone when you close the tab. We could not look at your project if we wanted to; the site is built so that there is nothing to look at.
The site is hosted on Cloudflare's static hosting platform. Like any web host, Cloudflare processes standard technical request data — such as IP address, browser type and the page requested — to deliver the site and protect it from abuse. That processing is governed by Cloudflare's own privacy policy. The site itself keeps no server-side database of visitors.
No analytics is currently installed on this site: nothing counts visits, tracks which calculators get used, or recognises a repeat visit. If analytics is added later, it will be switched on only together with an update to this page describing exactly what runs and what it collects — the policy is written to describe the site as it actually is, not as it might be.
The site sets no cookies, and because no analytics or advertising is currently installed, no analytics or advertising cookies are set either. If advertising is enabled in future, the advertising section below explains the additional cookies that may then appear. Blocking cookies in your browser does not affect the calculators in any way.
When advertising is enabled on this site, Google AdSense may serve ads and set advertising cookies, and Google may use those cookies to personalise the ads you see; you can control ad personalisation in your Google Ads Settings. No advertising is currently served on this site.
If you use the report-an-error form or email us, we receive what you send: the calculator and inputs you chose to report, and your email address if you provide one or write by email. That information is used only to check the calculation and reply to you. It is not added to any mailing list and is not shared with third parties.
Questions about this policy go to Ian Welkins at [email protected].
This site is run by Ian Welkins, who is responsible for the limited personal data described in this policy and can be reached at [email protected].
You can ask at any time what personal data we hold about you — in practice, only emails and error reports you have sent us — and ask for it to be corrected or deleted. Write to the address above and it will be done. Technical request data held by the hosting provider is processed under its own policy and is not used by us to identify individual visitors.
This policy is effective from 30 October 2026.
If this policy changes — for example, if advertising is enabled — the updated text will be published on this page with the change reflected in the relevant section before or at the time it takes effect. The version published here is the current one.