Privacy Policy

This Privacy Policy explains how Calculeaf ("Calculeaf", "we", "us") collects, uses, and protects information when you use the Calculeaf engineering calculation worksheet application and website (the "Service"). Calculeaf is operated by an individual sole operator based in the United Kingdom. We are the "data controller" for the personal data described below under the UK General Data Protection Regulation (UK GDPR) and the Data Protection Act 2018.

If you are in the UK, EU, or EEA, please also read our GDPR notice, which sets out your specific data-protection rights and our lawful bases for processing.

1. Information we collect

Account information

If you create an account or sign in with Google, we collect your email address and basic profile information returned by the sign-in provider (such as your name, where provided). We use this to identify your account and to save and load your worksheets.

Content you create

We store the worksheets you create, including their regions, expressions, text, plots, images, variables, and computed results. This content is associated with your account so it can be saved and retrieved. Worksheets created without an account may be stored temporarily and associated with your browser session or a share link.

Approximate location (from IP address)

When you load the Service, we use your IP address to estimate your country/region so we can choose a sensible default unit system (SI, USCS, or CGS). We do not use this to identify you personally and we do not store a precise location.

Usage and analytics data

We use Google Analytics to understand how visitors use the Service. This collects information such as pages viewed, approximate location, device and browser type, referring pages, and similar usage data, typically via cookies and similar technologies. This helps us improve the Service.

Technical and log data

Like most websites, our servers automatically record technical information such as your IP address, browser type, request times, and error logs. This is used to operate, secure, and troubleshoot the Service.

2. How we use your information

• To provide the Service — saving, loading, evaluating, and sharing your worksheets.
• To authenticate you and keep your account secure.
• To set sensible defaults, such as your unit system.
• To understand usage and improve the Service.
• To maintain the security, integrity, and reliability of the Service.
• To comply with legal obligations and respond to lawful requests.

3. Cookies and similar technologies

We use cookies and similar technologies for two purposes: (1) essential cookies that are required to sign you in and keep your session working, and (2) analytics cookies set by Google Analytics. You can control or block cookies through your browser settings. Blocking essential cookies may stop parts of the Service from working.

4. How we share information

We do not sell your personal data. We share information only as follows:

• Service providers. We use trusted third parties to operate the Service, such as Google (sign-in and analytics) and our hosting and infrastructure providers. They process data on our behalf or as independent controllers under their own terms.
• People you share with. If you create a share link to a worksheet, anyone with that link can view the shared content.
• Legal reasons. We may disclose information where required by law, or to protect our rights, users, or the security of the Service.

5. International transfers

Some of our providers (for example, Google) may process data outside the UK and EEA. Where this happens, we rely on appropriate safeguards such as the UK International Data Transfer Agreement, the EU Standard Contractual Clauses, or an adequacy decision.

6. Data retention

We keep your account information and worksheets for as long as your account is active or as needed to provide the Service. Analytics and log data are retained for a limited period. You can ask us to delete your account and associated content at any time (see "Your rights").

7. Security

We take reasonable technical and organisational measures to protect your information. However, no method of transmission or storage is completely secure, and we cannot guarantee absolute security.

8. Children

The Service is not directed to children under 16, and we do not knowingly collect personal data from children. If you believe a child has provided us with personal data, please contact us so we can delete it.

9. Your rights

Depending on where you live, you may have rights to access, correct, delete, or export your personal data, and to object to or restrict certain processing. If you are in the UK, EU, or EEA, see our GDPR notice for full details. To exercise any right, contact us using the details below.

10. Changes to this policy

We may update this Privacy Policy from time to time. When we do, we will revise the "Last updated" date above. Material changes will be communicated where appropriate.

11. Contact us