Privacy policy

Last updated: September 30, 2026

1. Who is responsible?

The controller for this website under the General Data Protection Regulation (GDPR) is:

2. The short version

• The calorie calculator works without an account. Your details (such as weight, height and age) are calculated and stored only in your browser. They are not sent to us.
• No advertising, no analytics or tracking tools, no profiling.
• Fonts, images and code are served from this website. Nothing is loaded from third parties (such as Google Fonts).
• The only technically necessary processing is hosting with Cloudflare, which processes your IP address when you open the site (see section 3).

3. Website delivery and security

Metably is delivered via Cloudflare Workers (Cloudflare, Inc., 101 Townsend St., San Francisco, CA 94107, USA). When you open the website, Cloudflare and its infrastructure process technical connection data, in particular your IP address, date and time, the requested address and information about your browser and operating system. This is necessary to deliver the site to you and to protect the service against attacks and abuse.

The legal basis is Article 6(1)(f) GDPR. Our legitimate interest is reliable, fast and secure delivery of the website.

Cloudflare processes data as our processor under its Data Processing Addendum and also processes certain network data for its own purposes, such as defending against attacks. Processing may take place outside the EU/EEA, in particular in the United States. Cloudflare is certified under the EU-US Data Privacy Framework (European Commission adequacy decision, Article 45 GDPR); in addition, the Data Processing Addendum includes EU standard contractual clauses (Article 46 GDPR).

We do not keep our own access logs. How long Cloudflare keeps technical data depends on the purpose (for example security) and is described in Cloudflare's Privacy Policy.

4. Your details in the calculator

So you don't have to enter your details again on your next visit, the calculator stores them in your browser's local storage (localStorage, key metably:calc). This only happens once you change a value yourself; simply opening the page stores nothing.

Stored are: units, pro mode, sex, age, height, weight, body fat (if entered), pregnancy or breastfeeding (if entered), workday activity, steps, training, goal, pace, and target weight and date.

Some of these details may be health data. The calculation runs entirely on your device, and your details are not sent to us or to anyone else. We have no access to them and therefore cannot view, export or delete them.

This storage does not expire. You can delete it at any time by clearing the site data for metably.app in your browser. The calculator still works without it; it just won't remember your details.

The legal basis for storing this on your device is Section 25(2)(2) of the German TDDDG, as it is strictly necessary for the function you request (a calculator that remembers your details).

5. Language cookie

If you switch the language at the top of the page, we set a cookie named metably_lang with the value "de" or "en". It makes metably.app open in your chosen language next time and is sent to our server with requests for that purpose. It contains no identifier and is not used for tracking. It is kept for one year, and you can delete it in your browser at any time.

Without this cookie, we choose the language based on your browser's language setting. The legal basis is Section 25(2)(2) TDDDG and, where personal data are involved, Article 6(1)(f) GDPR (our legitimate interest in showing the website in the language you want).

6. Contact by email

If you email us, we process your email address, your message and any details you provide in order to answer your enquiry. The legal basis is Article 6(1)(f) GDPR (our legitimate interest in responding) or Article 6(1)(b) GDPR where your enquiry concerns a contract or steps before one.

Our mailbox is hosted by Gmail (Google). Google processes messages and related technical data to provide the email service; this may involve processing outside the EU. See Google's Privacy Policy. Please only send the information needed for your enquiry and, if possible, no health data.

We keep correspondence as long as needed to handle your enquiry and then delete it, unless statutory retention duties (Article 6(1)(c) GDPR) or the establishment, exercise or defence of legal claims (Article 6(1)(f) GDPR) require longer storage.

7. No automated decisions

We do not make automated decisions within the meaning of Article 22 GDPR and do not create profiles. The calorie calculation runs only on your device and has no legal or similarly significant effect on you.

8. Your rights

Under the GDPR, and subject to its conditions, you have the right to:

• access the data we process about you (Article 15)
• rectification of inaccurate data (Article 16)
• erasure (Article 17)
• restriction of processing (Article 18)
• data portability (Article 20)
• object to processing based on Article 6(1)(f) GDPR on grounds relating to your particular situation (Article 21)

To exercise your rights, simply email us at the address above.

9. Right to lodge a complaint

You may lodge a complaint with a data protection supervisory authority, in particular in the EU member state of your habitual residence, place of work or of the alleged infringement. The authority responsible for us is:

10. Changes

We will update this privacy policy whenever Metably changes, for example when accounts and a weight diary are added. The version published here applies. Provider details are in our Legal Notice.