Privacy Policy

The data controller responsible for this website within the meaning of the General Data Protection Regulation (GDPR) is:

HelpfulCalculator is designed with privacy in mind. We collect minimal information to provide our calculator services:

• Server logs (IP address, timestamp, browser type, referrer URL, pages visited) — collected automatically by our hosting provider
• Technical information such as browser type, operating system, and device information
• Calculation inputs and results are processed entirely in your browser and are never sent to our servers

We process personal data based on the following legal grounds under Art. 6(1) GDPR:

• Legitimate interest (Art. 6(1)(f) GDPR): We use Sentry for error tracking and Vercel for hosting and content delivery. These are necessary to operate a secure and stable website.
• Consent (Art. 6(1)(a) GDPR): We load Google Analytics only after you accept analytics cookies in the consent banner. You can withdraw this consent at any time with effect for the future.

This website is hosted by Vercel Inc., 340 S Lemon Ave #4133, Walnut, CA 91789, USA. When you visit our website, Vercel's servers automatically collect and store information in server log files, including your IP address, date and time of the request, browser type, referrer URL, and the page visited.

Legal basis: Art. 6(1)(f) GDPR (legitimate interest in stable and secure website delivery).

Data may be transferred to the United States. Vercel participates in the EU-US Data Privacy Framework.

We use one essential cookie (calc_lang) to store your language preference. We also use your browser's localStorage to store calculation history and settings locally on your device — this data is never transmitted to our servers. For details, see our Cookie Policy.

We use Sentry (Sentry Inc., 45 Fremont Street, 8th Floor, San Francisco, CA 94105, USA) to detect and fix errors on our website. When an error occurs, Sentry collects error reports including stack traces, browser information, operating system, and your IP address.

Legal basis: Art. 6(1)(f) GDPR (legitimate interest in maintaining a stable and error-free service).

Data is transferred to the United States. Sentry participates in the EU-US Data Privacy Framework and uses Standard Contractual Clauses (SCCs) as additional safeguards.

If you accept analytics cookies in the consent banner, we use Google Analytics 4, a service provided by Google Ireland Limited (Gordon House, Barrow Street, Dublin 4, Ireland) and Google LLC (1600 Amphitheatre Parkway, Mountain View, CA 94043, USA). Google Analytics uses cookies such as _ga and _ga_* to measure how visitors use the site. We have configured IP anonymization (anonymize_ip) and do not enable advertising features. No data is transmitted before you grant consent.

Legal basis: Art. 6(1)(a) GDPR (your consent). You may withdraw your consent at any time with effect for the future by clicking "Cookie settings" in the footer.

Data may be transferred to the United States. Google participates in the EU-US Data Privacy Framework and relies on Standard Contractual Clauses as additional safeguards.

You can also opt out of Google Analytics by installing the browser add-on available at https://tools.google.com/dlpage/gaoptout.

Some of our service providers are located in the United States. Data transfers to the US are safeguarded by the following mechanisms:

• Vercel: EU-US Data Privacy Framework
• Sentry: EU-US Data Privacy Framework + Standard Contractual Clauses
• Google (Analytics 4): EU-US Data Privacy Framework + Standard Contractual Clauses

We retain data only as long as necessary for its purpose:

• Server logs (Vercel): Retained per Vercel's default retention period
• Error reports (Sentry): Retained per our configured Sentry retention period
• Analytics data (Google Analytics 4): Retained for the default 14-month period; deleted if you withdraw consent
• Browser localStorage (calculation history, language preference): Stored on your device until you clear your browser data

Your calculation data is processed locally in your browser and is not transmitted to our servers. We implement appropriate technical and organizational security measures to protect any data we do process, including encryption in transit (TLS/HTTPS) and access controls.

Under the GDPR, you have the following rights regarding your personal data:

• Right of access (Art. 15 GDPR): You can request information about the personal data we process about you.
• Right to rectification (Art. 16 GDPR): You can request correction of inaccurate personal data.
• Right to erasure (Art. 17 GDPR): You can request deletion of your personal data.
• Right to restriction of processing (Art. 18 GDPR): You can request that we restrict the processing of your data.
• Right to data portability (Art. 20 GDPR): You can request to receive your data in a structured, commonly used format.
• Right to object (Art. 21 GDPR): You can object to the processing of your data based on legitimate interest at any time. We will then no longer process your data unless we can demonstrate compelling legitimate grounds.
• Right to withdraw consent (Art. 7(3) GDPR): Where processing is based on consent, you may withdraw it at any time without affecting the lawfulness of prior processing.
• Right to lodge a complaint (Art. 77 GDPR): You have the right to lodge a complaint with a supervisory authority, in particular in the EU member state of your habitual residence, place of work, or the place of the alleged infringement.

If you have questions about this Privacy Policy or wish to exercise your data protection rights, please contact us through our website or the contact information provided in the Legal Notice (Impressum).

We may update this Privacy Policy from time to time. Changes will be posted on this page with an updated revision date. We recommend reviewing this page periodically.