Cookie Policy

Last updated: 2 October 2026

What is a cookie?

A cookie is a small text file that a website stores in your browser. It can be read back later, either by that site or, in the case of a third-party cookie, by the company that set it. Cookies are used for things like remembering a preference, keeping you signed in, or — as with advertising cookies — building a picture of the sites you've visited so ads can be more relevant.

Strictly necessary cookies

These run the basic functionality of the site and don't track you. They're set automatically and don't require consent.

Name	Purpose	Duration
theme	Remembers whether you last chose light or dark mode	Until you clear your browser data

Advertising cookies

We show advertising through Google AdSense to help cover the cost of running these free calculators. Google and its advertising partners use cookies to serve ads and measure how they perform, and — where you haven't opted out — to personalise ads based on your visits to this and other sites.

If you're visiting from the UK, EEA or Switzerland, Google's own certified consent message — not a banner of ours — asks for your choice on these advertising cookies before any personalised ads are shown, in line with UK and EU rules on advertising consent.

Name	Purpose	Duration
Google advertising cookies (e.g. DoubleClick/IDE)	Serves and measures ads, and limits how often you see the same one	Set by Google — typically up to 13 months
Other ad-partner cookies	Set by Google's advertising partners to support ad delivery on our pages	Varies by partner

We don't control what these cookies store or how long they last — that's set by Google and its partners. For the full detail, see Google's “How Google uses information from sites or apps that use our services” page.

How to control cookies

Turn off personalised ads: visit Google Ads Settings to opt out of personalised advertising from Google.
Opt out with other ad networks: the Your Online Choices site lists further opt-outs for other advertising partners.
Block cookies in your browser: every major browser lets you block or delete cookies, or ask to be notified before one is set, through its settings menu. Blocking all cookies may stop some parts of the site working as expected.

Changes to this policy

If the cookies we or our advertising partners use change, we'll update this page. See our Privacy Policy for how we handle personal data more generally.