Privacy notice

Last updated: 9 October 2026

Who I am

Plain Sums is run by Arthur Jones, an individual based in the UK. I am the controller of any personal data handled through this site under the UK GDPR and the Data Protection Act 2018. You can reach me through my Gumroad profile, which has a message option.

The short version

There are no accounts, no sign up and no ads, and no cookies are set. Nothing is stored in your browser. I count visits with Cloudflare Web Analytics, which gives me totals, not a record of you. Nothing you type into the calculators is sent to me.

The calculators

The calculators run entirely in your browser. What you type isn't saved or sent anywhere, and it's gone when you reload or close the page.

Hosting: GitHub Pages

The site is hosted on GitHub Pages, run by GitHub, Inc. When your browser asks for a page, GitHub receives your IP address and standard request details (such as browser type and the page requested), and may log them for security and to keep the service running. I don't get access to those logs. See GitHub's privacy statement.

Visit counts: Cloudflare Web Analytics

I use Cloudflare Web Analytics to see how many people visit and which pages they read. When a page loads, a small script from Cloudflare sends it the page address, the site you came from, basic browser details and how long the page took to load. It sets no cookies, doesn't use local storage and doesn't fingerprint your device.

All I see are totals: page views, referring sites, country and browser or device type. Cloudflare, Inc. handles the request data, including your IP address, as my processor. The lawful basis is legitimate interests: knowing which pages get used so I can improve them. If your browser or an ad blocker stops the script, the site works the same. See '+CF+'.

Gumroad

The templates are sold on Gumroad. Links to Gumroad only open when you click them. If you buy, Gumroad handles your payment and details under its own privacy policy, and tells me what was bought and the email address you gave so the files can be delivered.

If you message me

If you message me through Gumroad, I use your details and message only to reply, and delete them once they're no longer needed for that. The lawful basis is legitimate interests: answering the message you sent.

Transfers outside the UK

GitHub and Cloudflare may process request data outside the UK, including in the United States, under their own safeguards.

Your rights

You have the right to ask for access to, correction of or deletion of your personal data, and to object to or restrict how it's used. If you're unhappy with how I've handled your data, you can complain to the Information Commissioner's Office at ico.org.uk.