Privacy Policy

What we collect

When you create an account, we collect your email address and store the projects and calculations you choose to save. Calculator inputs, unit preferences and plans are stored locally in your browser (localStorage) and, if you are signed in, optionally synced to your account. We also collect anonymous usage statistics (see Analytics below).

Analytics

We use Google Analytics 4 to understand how the site is used — for example which calculators and guides are opened, when a plan is created or exported to PDF, and general traffic sources. We do not collect names or other directly identifying details in analytics.

Analytics runs under Google's Consent Mode. Until you accept analytics cookies, Google Analytics operates in a cookieless mode that collects only aggregated, anonymous measurements. If you accept, Google Analytics sets cookies to measure returning visits more accurately. You can accept or decline at any time, and change your choice later via “Cookie settings” in the page footer. Data is processed by Google; see Google's own privacy resources for details, and note that analytics data may be retained for up to 14 months.

Your choice is remembered in your browser for six months, after which we ask again — consent should be a current decision, not one you made once and cannot revisit. We also ask again if we ever add a new purpose, so an answer you gave before it existed is never treated as agreement to it. Declining is remembered for exactly as long as accepting.

Advertising

We sometimes pay to advertise MaterialCalc on Google. If you choose “Accept all” in the cookie banner, Google may set cookies that let us see whether a visit that began with one of our adverts later led to a purchase. That is the only thing we use them for: measuring whether the advertising was worth paying for.

These cookies are off by default and are never set unless you choose “Accept all”. Choosing “Analytics only” or “Decline all” leaves them switched off, and you can change your mind at any time via “Cookie settings” in the footer.

We do not sell your data, we do not show adverts on this site, and we do not build advertising profiles about you. We also record which advert or link brought you here in your own browser's local storage so we can attribute a purchase to a campaign — that stays on your device and is sent to us only if you buy something.

Cookies and local storage

MaterialCalc uses browser localStorage to save your calculator settings, unit preferences and projects between sessions, and authentication cookies (via Supabase) when you are signed in. These are strictly necessary for the site to function and are always active.

Analytics and advertising-measurement cookies are only set if you consent via the cookie banner, and they are two separate choices — you can allow analytics without allowing advertising measurement. We do not use cookies to show you adverts on other sites, and we do not share your data with advertising networks for their own purposes.

Legal basis

We process account data to provide the service you request (performance of a contract). Analytics and advertising-measurement cookies are processed only on the basis of your consent, given separately for each purpose, which you may withdraw at any time without affecting prior processing.

Your rights

You have the right to access, correct or delete your personal data, to object to or restrict processing, to data portability, and to withdraw analytics consent. You can withdraw consent via “Cookie settings” in the footer, delete locally stored data by clearing site data in your browser, and request account deletion by contacting us. If you are in the EU/EEA, you also have the right to lodge a complaint with your local data protection authority.

Third parties

We use Supabase for account authentication and data storage, Google Analytics for usage measurement, and Vercel for hosting. We do not sell your data to third parties.

Contact

For privacy questions or to exercise your rights, contact us via our Contact page.