Body Numbers
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Privacy Policy

Effective 2026-09-25. Last updated 2026-09-29.

This policy explains what personal data we collect when you use the Body Numbers app (published on Google Play as “BMI Calculator: TDEE, Body Fat”, package com.selanto.bodycalculator, “the app”) and the website bodynumbers.app (“the website”), why we collect it, who receives it, and what your rights are. It follows the EU General Data Protection Regulation (GDPR) and Dutch law. This policy exists in English only and the English text prevails.

In short

  • The app works with no account. Your measurements then stay on your phone and we never see them.
  • Nothing you measure is uploaded unless you sign in and turn on cloud sync, which is part of the optional Plus purchase.
  • If you do sign in, the cloud copy is stored in the Netherlands.
  • The free version shows ads, which involve Google. The Plus purchase removes them.
  • We do not sell your data, and we never use your body measurements for advertising.

1. Who is responsible for your data

Selanto Apps, a sole proprietorship (eenmanszaak) registered in Rotterdam, the Netherlands.

We are the data controller for the processing described here.

2. Data that stays on your phone

By default the app has no account and sends nothing. The following is written to a database on your device and stays there:

  • The profiles you create: a name if you give one, sex, month and year of birth, height, weight, and any waist, neck or hip measurement.
  • Each saved reading, with the date it was taken, so the app can tell you what changed since last time.
  • Any child or teenager profile you add for the growth check.
  • Your settings: units, which BMI cut points you chose, activity level, reminders.

We cannot see any of this. If you uninstall the app without turning on cloud sync, it is gone.

If your phone’s own backup is switched on, this database may be included in that backup, which is handled by Google under their terms, not ours. The app lets you exclude it.

3. Data collected only if you sign in

Signing in is optional and exists for one reason: to carry your history to another device. It is part of the Plus purchase.

You can sign in with Google or with Apple. We then receive and store:

  • A user identifier from the sign in provider.
  • Your email address, unless you use Sign in with Apple and choose to hide it, in which case we receive a relay address instead.
  • A copy of the profiles, readings and settings described in section 2.

The cloud copy is held in Cloud Firestore in the Netherlands (Google Cloud region europe-west4), so it does not leave the European Union. Your phone remains the source of truth: a sync pass uploads what changed on the device and downloads what changed in the cloud, and the newer record wins.

4. Data collected from every install

  • Crash reports. If the app crashes we receive a crash report through Firebase Crashlytics: device model, operating system version, app version, and a stack trace. These contain no measurements.
  • Advertising. The free version shows ads served by Google AdMob. Google may process your device’s advertising identifier and similar data to select and measure ads. Their handling is described in Google’s privacy policy and their advertising terms. Buying Plus removes ads.
  • Abuse prevention. Firebase App Check is used to confirm that requests come from a genuine copy of the app.
  • Purchases. If you buy Plus, RevenueCat and the Google Play billing system handle the transaction. We receive confirmation that an entitlement is active. We never receive your payment card details.
What Why Legal basis
Measurements on your device To calculate and show your results Contract (article 6(1)(b))
Cloud sync, if you enable it To carry your history between your devices Contract (article 6(1)(b))
Crash reports To find and fix faults Legitimate interest (article 6(1)(f))
Ads in the free version To fund a free app Consent where required, otherwise legitimate interest
Abuse prevention To stop fraudulent use of our backend Legitimate interest (article 6(1)(f))
Website analytics To see which pages are used and which lead people to the app Legitimate interest (article 6(1)(f))

Body measurements can be health related data. We treat them as such: they are processed on your device for your own use, and they leave it only on your explicit instruction when you turn on sync.

6. Who else receives data

  • Google (Firebase Authentication, Cloud Firestore, Cloud Functions, App Check, Crashlytics): hosting and infrastructure for the optional account and sync.
  • Google (AdMob): advertising in the free version.
  • Google Play: distribution and billing.
  • RevenueCat: purchase and entitlement management.
  • Vercel: hosting for the website, and its cookie-free page view analytics.
  • Ahrefs: cookie-free website analytics, so traffic sits beside our search ranking data in one tool. Ahrefs Pte. Ltd. is based in Singapore.

We do not sell personal data and we do not share your measurements with advertisers.

7. International transfers

Your synced data is stored in the European Union. Some of the providers above are established in the United States and may process limited operational data there, under the European Commission’s standard contractual clauses or an adequacy decision.

Ahrefs is established in Singapore, which has no European Commission adequacy decision, so the website analytics data described in section 14 is transferred under the European standard contractual clauses. You can ask us for a copy of the safeguards.

8. How long we keep data

  • Data on your phone: until you delete it or uninstall the app.
  • Synced data: until you delete your account, after which it is removed from our systems.
  • Crash reports: retained by Firebase Crashlytics according to Google’s published retention periods.

9. Deleting your data

You can delete everything yourself. The delete your data page explains how, both on the device and in the cloud. If you signed in with Apple, deleting the account also revokes the Sign in with Apple token rather than leaving it attached to your Apple account.

10. Your rights

Under the GDPR you may request access to your data, correction, deletion, restriction of processing, portability, and you may object to processing based on legitimate interest. Write to support@bodynumbers.app and we will respond within 30 days.

You may also lodge a complaint with the Dutch data protection authority, the Autoriteit Persoonsgegevens.

11. Children

The app includes a growth check for children and teenagers aged 5 to 19, intended to be used by a parent or carer on their own device. A child’s measurements are stored in the same way as anyone else’s: on the phone, and in the cloud only if the account holder has turned sync on. We do not knowingly create accounts for children under 16.

12. Security

Data in transit is encrypted. Access to the cloud copy is restricted to the signed in account. Requests to our backend are checked with App Check. No system is perfect, and we will notify you and the regulator of a breach where the law requires it.

13. Automated decisions

The app performs calculations and shows you the result against published reference ranges. It makes no automated decision that produces a legal or similarly significant effect, and it does not profile you.

14. The website

The website sets no cookies and stores nothing on your device. Nothing you type into a calculator is ever sent anywhere: every calculator runs in your browser, on your own device, and the page has nowhere to send it to. That has not changed and is not going to.

It is hosted by Vercel, whose servers necessarily process your IP address to deliver the page, and who keep short lived operational logs.

Since 29 September 2026 the website counts page views. An earlier version of this section said we ran no analytics at all and promised to say so before that changed, which is what this paragraph is. Two tools do the counting, both without cookies:

Vercel Web Analytics records the page you viewed, roughly where in the world you are, the kind of device, and the site you arrived from. To count a visitor only once a day it makes a salted hash of your IP address and browser details that cannot be turned back into your IP address, and no raw IP address is kept in the analytics data. It also records when someone taps a link to the Google Play listing, along with which page that link was on, so we can see which pages actually help people find the app. That event carries no personal data.

Ahrefs Web Analytics loads a small script from Ahrefs and records the same shape of thing: the page, the site or search engine you came from, your approximate country, and your device and browser type. It sets no cookies and does not identify you. This is the one external script the site loads, and it is why the content security policy allows that one host and no other.

The legal basis for both is our legitimate interest in knowing how the site is used (article 6(1)(f)). Neither builds a profile of you, follows you to other sites, or feeds advertising. You can object at any time using the contact details below, and most browsers and tracker blockers will stop both scripts if you would rather not be counted at all.

15. Changes to this policy

If this policy changes materially we will update the date above and, where the change is significant, say so in the app.

16. Contact

support@bodynumbers.app, or Selanto Apps, Rotterdam, the Netherlands, KvK 75803097.

This is not medical advice. Body Numbers is a calculator. It does not diagnose, treat or monitor any condition, and no number it produces should replace a conversation with a doctor or a dietitian. If a result worries you, or if you are pregnant, unwell, or under eighteen, speak to a health professional.

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