Legal
Privacy Policy
Last updated: June 9, 2026
Kalkul is built to run on your device, not in the cloud. This policy explains the limited ways we interact with your data — and how we keep that interaction to a minimum.
Information We Collect
Data You Create
Kalkul stores calculation history, saved expressions, favorite units, and favorite time zones locally on your device using Hive and SharedPreferences. This data never leaves your device unless you explicitly export a backup.
Currency Rate Fetching
To display currency exchange rates, Kalkul connects once per day to Firebase Realtime Database — a Google service. No personal data is sent during this request. Only the exchange rate data is retrieved.
No Account Required
Kalkul does not ask you to create an account, sign in, or provide any personal information such as your name, email address, or phone number.
How We Use Your Data
Local Functionality Only
Your calculation history, settings, and preferences are used solely to power the app's features on your device. We do not analyze, monetize, or transmit this data.
Currency Rates
Exchange rate data is fetched from our Firebase database to provide up-to-date currency conversions. Rates are updated once daily — there is no real-time market monitoring.
Third-Party Services
Firebase (Google)
Kalkul uses Firebase Realtime Database to serve currency exchange rates. Google's privacy practices apply to this connection. You can review Google's Privacy Policy at policies.google.com/privacy.
No Advertising Networks
Kalkul contains no ads and integrates no advertising SDKs. We do not share data with marketing or analytics platforms.
No Crash Analytics
Kalkul does not currently integrate crash reporting or usage analytics services.
App Permissions
Internet
Required to fetch daily currency exchange rates from Firebase.
Storage / File Access
Used only when you choose to export or import a backup file (.kalkul). We do not access any other files on your device.
Vibration
Used for optional haptic feedback on calculator button presses. Enabled or disabled in Settings.
Wake Lock
Used to keep your screen on while using the app, when the 'Keep Screen On' setting is enabled.
Data Retention & Deletion
Your Control
All data stored by Kalkul lives on your device. You can clear calculation history inside the app at any time. Uninstalling Kalkul removes all locally stored data permanently.
Backup Files
If you export a backup, that .kalkul file is saved to a location you choose and is your responsibility to manage.
Children's Privacy
Kalkul is a general-purpose calculator app suitable for all ages. We do not knowingly collect personal data from anyone, including children under 13.
Health & Medical Disclaimers
The BMI, body fat, BMR, and ovulation calculators in Kalkul are provided for informational and educational purposes only. They are not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider with questions about your health.
Changes to This Policy
We may update this Privacy Policy from time to time. The 'Last updated' date at the top of this page will reflect any changes. Continued use of Kalkul after changes are posted constitutes your acceptance of the updated policy.
Contact
If you have questions or concerns about this Privacy Policy, please reach out to us at the contact details listed on our app store page.
© 2026 Kalkul. All rights reserved.