Privacy policy

What do we collect?

Measurement data, described in the next section, plus the host's standard server logs. There is no account, no newsletter, no comment system, no advertising script and no form that asks for personal details. Fonts and page scripts are served from our own server.

When you use a calculator, the dimensions and settings you enter are processed by JavaScript in your browser. They are not sent to our server, not added to the page address and not saved. Calculators embedded on other websites load no measurement tags at all.

How does the site use Google Tag Manager and analytics?

Every page on this site loads Google Tag Manager, a Google service that loads the site's measurement tags, such as Google Analytics. These tags record things like the pages viewed, how a visit arrived (for example from a search engine), the device and browser type, approximate location derived from the IP address, and how long pages are read. They use cookies or similar browser storage to tell one visit from another.

The data is used in aggregate to see which calculators and guides are useful and which need work. It is not used to build advertising profiles, and BuildersCalcs does not sell it. Google processes it under its own terms and privacy policy.

You can limit or block it: most browsers can block third-party cookies or tracking scripts, content blockers stop Google Tag Manager from loading, and Google offers a browser add-on that opts you out of Google Analytics. Every page and calculator works with these blocked.

What does your browser store?

Apart from the measurement cookies above, one setting: whether you chose US or metric units on a calculator. It is saved in your browser's localStorage under the name bc-units, so the next calculator opens in the same units. It stays on your device, is never sent to us and contains nothing about you. You can remove it by clearing the site data for this site in your browser settings. If your browser blocks storage, the calculators still work and simply start in US units each time.

What can Amazon see?

Some pages list products with links to Amazon. Two things follow from that:

• Product images load from Amazon's servers. On a page with product listings, your browser fetches the pictures from Amazon's image servers. Like any web request, this passes Amazon your IP address and basic browser details. Amazon's own privacy notice covers what it does with them.
• Clicking a link takes you to Amazon. Our links carry an Associates tracking tag so that Amazon can credit a purchase to this site. Once you are on Amazon, it may set its own cookies, and your visit is covered by Amazon's privacy notice, not this one. We receive only Amazon's reports of orders and commission, which do not identify you to us.

How these links work and how products are chosen is explained in our affiliate relationships.

What does our host log?

The server that hosts the site keeps standard access logs, as almost every web server does. A log entry typically records the IP address that made the request, the date and time, the page or file requested, the browser's user-agent string and the referring page. These logs are used to keep the site running and secure, for example to find errors and block abusive traffic. They are not used to build profiles of visitors, they are not combined with other data, and they are not sold or shared for marketing.

What if you write to us?

When a contact address is published on the contact us page, anything you send will be used only to deal with your correction or question. Your address and message will not be added to a mailing list or passed to anyone else.

What are your rights?

If you are in the UK or the European Economic Area, data protection law gives you rights to see, correct or delete personal data held about you, and to object to how it is used. In practice the personal data connected with a visit is the measurement data Google Analytics records, the IP address in the host's logs, and anything you choose to send us. You can ask about either through the contact page once the address is published. You can also complain to your national data protection authority, which in the UK is the Information Commissioner's Office.

The site is written for adults planning building work and is not directed at children.

When will this policy change?

Before anything described here changes. If advertising or any other script that collects data is added, or the measurement described above changes, this page will be updated first to say what is collected, by whom and how to opt out, and the date below the title will change. For background on the site, see who builds these calculators. To get back to the calculators, use back to the main calculator index page, or see the HTML sitemap.