Privacy Policy
Last updated: 14 June 2026. This policy explains how we process personal data when you visit HalfLifeCalc, in accordance with the EU General Data Protection Regulation (GDPR), the German Federal Data Protection Act (BDSG) and the German Telecommunications Digital Services Data Protection Act (TDDDG).
1. Controller
The controller responsible for data processing on this website within the meaning of Art. 4 (7) GDPR is:
Erik Winkel
Rosenfelder Ring 64
10315 Berlin, Germany
Email: erikwinkel@posteo.de
Phone: +49 170 4725103
2. Overview of Processing
HalfLifeCalc is an informational website that does not require registration. All pharmacokinetic calculations run entirely in your browser; the values you enter (medication, dose, etc.) are not transmitted to or stored on our servers. The website is financed through third-party advertising (Google AdSense), which involves further data processing as described below. All fonts and scripts required to render the site are served from our own infrastructure — no requests are made to third-party CDNs.
3. Server Log Files
When you visit our website, our hosting provider automatically collects technical access data in server log files transmitted by your browser:
- IP address of the requesting device (truncated or anonymised where possible)
- Date and time of the request
- Name and URL of the requested file
- HTTP status code and amount of data transferred
- Referrer URL (if any)
- Browser type, version and operating system
Purpose: Ensuring a secure and stable connection, network and information security (Art. 32 GDPR), and troubleshooting.
Legal basis: Art. 6 (1) (f) GDPR (legitimate interest in operating a secure and functional website).
Storage period: Log files are stored for a maximum of 14 days and then deleted, unless retention is required to investigate a concrete security incident.
4. Consent Management (CMP)
Before any non-essential cookies or third-party services are loaded, we obtain your consent via a Google-certified consent management platform (Google Funding Choices, provided by Google Ireland Ltd., Gordon House, Barrow Street, Dublin 4, Ireland). The CMP implements the IAB Europe Transparency & Consent Framework (TCF v2.2) and Google's Additional Consent Mode v2.
When you visit the site for the first time, a consent banner is displayed at the bottom of the screen offering equally weighted "Accept", "Reject" and "Manage options" buttons. Your choice is stored in a first-party cookie and signalled to all integrated vendors. Until you have given consent, no advertising cookies are set, only non-personalised "limited ads" may be shown (where permitted), and Google's signals are sent without identifiers.
Legal basis: Art. 6 (1) (c) GDPR in conjunction with § 25 (1) TDDDG (legal obligation to obtain consent for non-essential storage on the user's device) and Art. 6 (1) (f) GDPR (legitimate interest in complying with this obligation).
Withdrawal of consent: You can withdraw or change your consent at any time by clicking the "Privacy Settings" link in the footer of any page. The withdrawal takes effect for the future; it does not affect the lawfulness of processing carried out before the withdrawal.
5. Google AdSense
This website uses Google AdSense, a service for integrating advertisements, provided by Google Ireland Ltd., Gordon House, Barrow Street, Dublin 4, Ireland ("Google"). Google AdSense uses cookies and similar technologies (such as web beacons and local storage) that enable the analysis of your use of the website. Information collected may be transmitted to and stored by Google on servers in the United States.
Purposes of processing:
- delivery and display of advertisements (including personalised advertising based on your interests, where you have consented);
- frequency capping (limiting how often you see the same ad);
- ad measurement and reporting (e.g. how often an ad was shown or clicked);
- fraud and abuse prevention, security and debugging;
- aggregated audience and market research.
Categories of personal data processed: IP address; user-agent string; referrer URL; pages visited on this website; ad-interaction data (impressions, clicks, viewability); approximate location derived from the IP address; pseudonymous online identifiers stored in cookies, local storage or device-graph signals; consent signals (TCF / Additional Consent string).
Legal basis: Art. 6 (1) (a) GDPR and § 25 (1) TDDDG (your consent given via the CMP). Without consent, only "non-personalised ads" or "limited ads" within the meaning of Google's policies may be delivered, which still requires technically necessary processing of IP address and request data on a legitimate-interest basis (Art. 6 (1) (f) GDPR) in order to display the page at all.
Storage period: The lifetime of the individual cookies is set out in the cookie table in section 7. You can also delete cookies at any time via your browser.
Opt-out and ad settings: You can disable personalised advertising at any time via Google's ad settings (adssettings.google.com) or, for participating providers, at youronlinechoices.eu. For further information about how Google handles your data, see Google's privacy policy at policies.google.com/privacy and Google's overview of advertising at policies.google.com/technologies/ads.
6. Joint Controllership (Art. 26 GDPR)
For the collection of personal data in your browser via the AdSense tags (in particular cookies, the reading of device characteristics, and the transmission of these data to Google), we and Google are joint controllers within the meaning of Art. 26 GDPR. The essential content of the joint-controller arrangement is set out in Google's Controller-Controller Data Protection Terms. Beyond the joint collection in your browser, Google processes the data as an independent controller for its own purposes; we have no influence on that processing. Regardless of the joint-controllership arrangement, you may exercise your data-subject rights against either of us; we will forward your request to Google where appropriate.
7. Cookies and Local Storage
The following table lists the cookies and similar storage technologies used on this website. Strictly necessary entries are set without consent; all others are only set after you have given consent via the CMP.
| Name | Provider | Purpose | Lifetime | Category |
|---|---|---|---|---|
| FCCDCF / FCNEC | Google Funding Choices | Stores your consent choices (TCF v2.2 string) | up to 13 months | Strictly necessary |
| halflifecalc_prefs | HalfLifeCalc (first-party) | Remembers your last selected medication / unit (local storage) | persistent until cleared | Strictly necessary |
| __gads, __gpi | Google AdSense | Frequency capping, ad personalisation | up to 13 months | Advertising (consent) |
| IDE | Google (doubleclick.net) | Ad measurement, conversion tracking, personalisation | up to 13 months | Advertising (consent) |
| NID, ANID | User preferences, advertising personalisation | up to 13 months | Advertising (consent) | |
| test_cookie | Google (doubleclick.net) | Verifies that the user's browser supports cookies | 15 minutes | Advertising (consent) |
8. International Data Transfers
When Google AdSense is used, personal data may be transferred to recipients in the United States and other third countries. Google LLC is certified under the EU-US Data Privacy Framework (dataprivacyframework.gov), so transfers to Google LLC are covered by the European Commission's adequacy decision of 10 July 2023 (Art. 45 GDPR). To the extent transfers are not covered by an adequacy decision, they are based on the EU Standard Contractual Clauses (Art. 46 (2) (c) GDPR), supplemented where necessary by additional technical and organisational measures.
9. Contact by Email
If you contact us by email, the information you provide (email address, content of the message) is processed solely for the purpose of handling your request. The legal basis is Art. 6 (1) (b) GDPR if your request relates to a (pre-)contractual matter, otherwise Art. 6 (1) (f) GDPR (legitimate interest in answering inquiries). Your message is deleted once it is no longer required, unless statutory retention obligations apply.
10. Your Rights as a Data Subject
You have the following rights with regard to your personal data:
- Right of access (Art. 15 GDPR)
- Right to rectification (Art. 16 GDPR)
- Right to erasure (Art. 17 GDPR)
- Right to restriction of processing (Art. 18 GDPR)
- Right to data portability (Art. 20 GDPR)
- Right to object to processing based on Art. 6 (1) (f) GDPR (Art. 21 GDPR) — including against direct marketing
- Right to withdraw consent at any time with effect for the future (Art. 7 (3) GDPR)
To exercise your rights, please contact us using the details in section 1.
11. Right to Lodge a Complaint
You have the right to lodge a complaint with a supervisory authority, in particular in the Member State of your habitual residence, place of work, or place of the alleged infringement (Art. 77 GDPR). The supervisory authority competent for the controller is:
Berliner Beauftragte für Datenschutz und Informationsfreiheit
Alt-Moabit 59–61, 10555 Berlin, Germany
www.datenschutz-berlin.de
12. No Obligation to Provide Data; No Automated Decision-Making
You are not legally or contractually obliged to provide any personal data to use this website. We do not use automated decision-making, including profiling, that produces legal effects concerning you or similarly significantly affects you, within the meaning of Art. 22 GDPR.
13. Data Security
We use transport encryption (TLS/HTTPS) and appropriate technical and organisational measures (Art. 32 GDPR) to protect your data against accidental or intentional manipulation, loss, destruction, or unauthorised access.
14. Changes to this Policy
We may update this privacy policy from time to time to reflect changes in our service, in integrated third-party services, or in applicable law. The current version is always available at this URL.