Privacy Policy

Last updated: 1 August 2026
This policy explains what the 3D Print Calculator app and website collect, why, and what control you have over it. It covers the iOS app, the Android app and the website at www.3dprintcalculator.net, which share one account and one backend.

Who is responsible

3D Print Calculator is built and operated by Paul Sohier, an individual developer, who is the data controller for the personal data described here. You can reach us at [email protected] for any privacy question or request.

What we collect

You can use the calculator without an account. If you create one, we store:
• Your username and email address
• Your password, stored only as a salted hash — we never see or store it in readable form
• Whether your email address has been verified
• Your preferred currency
When you save your work, we store the content you enter:
• Your calculations — filament type, colour, weight, prices, labour entries and machine settings
• Your saved filaments and printers
We also keep standard server logs, which include your IP address and the time of each request, to keep the service running and to investigate abuse.

Why we use it

We use your account data to sign you in, to keep your saved work attached to you, and to send you the transactional emails the service depends on — email verification and password resets. We use your calculations solely to show them back to you and to generate the PDF exports you ask for. We do not use any of it to build a profile of you.

Who we share it with

We do not sell your personal data, and we do not share it for advertising. We rely on the service providers listed below, and only for the purposes given:
• Sentry — crash and error reporting. When something goes wrong, Sentry receives the error, the app version, your device model and operating system version. If you are signed in it also receives your numeric account ID, so we can tell whether a problem affects one person or everyone. The app is configured not to send personal data with these reports: Sentry never receives your username, email address, password, or the contents of your calculations.
• Cloudflare Turnstile — the anti-bot check on the registration form. This runs on the website only; the iOS and Android apps do not use it.
Verification and password-reset emails are sent from our own mail server. We do not pass your email address to a third-party email or marketing service, and we never send you marketing email.
Beyond the two services above, we disclose personal data only where the law requires it.

What we do not do

The app contains no advertising, no advertising SDKs and no analytics or tracking SDKs. We do not use Google Analytics or Google AdSense, we do not track you across other apps or websites, and we do not sell or rent your data to anyone.

Data stored on your device

The mobile apps keep your sign-in token in the device's secure storage — the iOS Keychain or the Android Keystore. If you make changes while offline, they are held on your device until they can be synced. Signing out removes both.

Deleting your account

You can delete your account at any time from Profile → Delete account, in both the mobile apps and on the website, or from our account deletion page. Deletion is immediate and permanent: your account and every calculation, filament and printer saved to it are erased and cannot be recovered. You can also request deletion by emailing [email protected] from your account's email address.
Server logs and backups age out on their own schedule and are not retained beyond what is needed to run the service securely.

Your rights

You can access and correct your account details in the app, export your calculations as PDF, and delete your account as described above. Depending on where you live you may also have the right to a copy of your data or to object to how we use it — write to [email protected] and we will respond within 30 days. We may ask you to confirm you own the account before we act.

Children

The service is not directed at children under 16 and we do not knowingly collect their data. If you believe a child has given us personal data, contact [email protected] and we will remove it.

Cookies

The website uses cookies only to keep you signed in and to keep the site working. There are no advertising or analytics cookies. The mobile apps do not use cookies.

Changes to this policy

If this policy changes materially we will update the date at the top and, where the change affects how we use your data, tell you in the app.
Questions about this policy? Email [email protected].