Privacy Notice

This English text is provided for convenience. For German users, the German version at /de/privacy is the authoritative version.

Effective: 2026-05-17

This notice explains how CalcLibrary processes personal data. The website is currently a static calculator site. Calculations run in the browser. There are currently no user accounts, no comment features, and no server-side storage of calculator results.

Controller

Benjamin Kannel
Kalkhofstraße 9
70567 Stuttgart
Germany
Email: info@calclibrary.io

Hosting and technical logs

The website is hosted via Vercel. When you access the site, the hosting provider processes technically necessary connection and access data such as IP address, timestamp, requested resource, referrer, and browser or device information. This is necessary to deliver the site, defend against attacks, maintain stability, and investigate errors. The legal basis is Art. 6(1)(f) GDPR.

The exact retention period for technical logs depends on the hosting provider's operational settings and the specific security or incident context. We do not use these logs to build user profiles.

Local browser storage

The site uses local browser storage for functional purposes. At the moment this mainly covers theme mode, the preferred unit system, and your choice regarding optional calculator analytics. This information stays on your device until you delete or change it in your browser.

Consent management

Optional calculator analytics with PostHog are only activated after your explicit choice. Your choice is stored locally in the browser so the site can respect it. You can change or withdraw that choice at any time through the "Privacy settings" link in the footer. The legal basis for optional calculator analytics is Art. 6(1)(a) GDPR.

Cookie-free traffic and performance measurement with Vercel Web Analytics and Vercel Speed Insights is separate from this and runs independently of the PostHog consent choice. Details follow in the next section; the legal basis is Art. 6(1)(f) GDPR.

Cookie-free traffic and performance measurement with Vercel

Vercel Web Analytics and Vercel Speed Insights are active across the entire site. These services run without the PostHog consent toggle, do not set cookies, and according to the provider do not store unique visitor identifiers. We use the measurement for aggregate traffic and performance values, to monitor reliability and load times, and to prioritize improvements. The data is not intended, and is not used by us, to identify individual visitors. Vercel acts as a processor for this data.

Calculator analytics (PostHog) - only with consent

If you consent, we use PostHog Cloud EU for calculator product analytics. We send only two intentionally instrumented events:

• calculator_viewed when a calculator page mounts,
• calculator_result_shown when the first valid result renders in that session,

each carrying the properties calculator_id, category, and locale. We do not send calculator inputs, result values, query strings, autocaptured interactions, pageviews, session replays, heatmaps, or surveys to PostHog.

To distinguish returning visits from first visits, PostHog stores a long-lived identifier in localStorage and in a cookie on the calclibrary.io domain. We do not link user accounts, and do not call identify(). The legal basis is Art. 6(1)(a) GDPR.

Cookies and similar technologies

This site only sets cookies where strictly functional or after your consent. The consent choice itself and functional preferences (theme, unit system) live solely in your browser's localStorage. A PostHog cookie is set additionally only after you have consented to calculator analytics; if you withdraw consent, client-side capture is stopped.

Recipients and service providers

At the moment we mainly use the following recipients or processors for site operation:

• Vercel Inc. for hosting and technical logs.
• Vercel Inc. for cookie-free Web Analytics and aggregate traffic measurement.
• Vercel Inc. for cookie-free Speed Insights and aggregate performance measurement.
• PostHog Inc. for optional calculator analytics via the EU cloud region (only after consent).

International transfers and safeguards

Depending on the provider, support operations, corporate structure, or administrative access may create links to countries outside the EEA. Where a transfer to a third country takes place, we rely on the safeguards required under data protection law, such as an adequacy decision or appropriate contractual safeguards offered by the provider.

Advertising and marketing

We do not currently actively use advertising or marketing tracking technologies. If we introduce advertising, remarketing, or comparable technologies later, they will only be activated after any required prior consent. This notice and the privacy settings will be updated before that happens.

Retention

Browser-stored preferences and the consent choice remain until you delete or overwrite them. Vercel Web Analytics and Vercel Speed Insights store cookie-free, aggregate traffic and performance values according to the provider's retention periods. PostHog retains event-level calculator analytics data, in the current configuration, for the provider's default period of approximately one year, after which data is aggregated or deleted.

Your rights

Under the GDPR you may in particular have rights of access, rectification, erasure, restriction of processing, data portability, and objection to processing based on legitimate interests. Any consent you provide can be withdrawn at any time with effect for the future.

Right to complain

You have the right to lodge a complaint with a data protection supervisory authority, in particular in the Member State of your habitual residence, place of work, or the place of the alleged infringement.

Changes to this notice

We update this privacy notice when the website, service providers, or legal requirements change. The version published on this page is the current version.