CalcCircuit Privacy Policy
Last updated: 2026-08-27

CalcCircuit ("we", "our", "us") respects your privacy. This policy explains what data we
collect, how we use it, and what choices you have. It is written in plain English and
designed to comply with the EU General Data Protection Regulation (GDPR), the California
Consumer Privacy Act (CCPA/CPRA), and Google's AdSense program policies.

1. Data we collect
We collect three categories of data:
  - Data you provide directly: email (newsletter, account), optional note text on saved
    calculations.
  - Data collected automatically: anonymous usage analytics (pages viewed, button clicks,
    calculation types), aggregated traffic source, device type, browser, country (from IP,
    not stored in full), and timestamps.
  - Data from third parties: Google AdSense and Google Analytics 4 may set cookies and
    collect information as described in their own policies.

We do NOT collect your financial inputs or calculation results. All calculations run in
your browser; only the result text and tool slug are optionally sent to our analytics
endpoint for usage statistics.

2. How we use your data
  - To provide, maintain, and improve our calculators and tools.
  - To remember your preferences (theme, saved calculations, consent choices).
  - To send you newsletters if you have explicitly subscribed (one-click unsubscribe).
  - To generate anonymous usage statistics and detect abuse.
  - To display ads through Google AdSense.
  - To respond to legal requests when required by law.

3. Cookies and similar technologies
  - Essential: theme, consent record, saved calculations. Required.
  - Analytics: Google Analytics 4 (_ga, _ga_*) — only if you accept analytics.
  - Advertising: Google AdSense (__gads, __gpi, IDE) — only if you accept personalized ads.
    If you reject, we set requestNonPersonalizedAds=1 for non-personalized ads.

Change or withdraw consent at any time by clearing the calccircuit_cookie_consent
localStorage key and reloading.

4. Local storage
We use your browser's localStorage to remember saved calculations and theme. This data
never leaves your device unless you explicitly choose to sync it via cloud sync. Clear it
from your browser settings or via the "Clear All" button on /saved.

5. Third-party services
  - Google AdSense — https://www.google.com/settings/ads (opt out)
  - Google Analytics 4 — https://tools.google.com/dlpage/gaoptout (opt out)
  - Cloudflare Pages & D1 — https://www.cloudflare.com/privacypolicy/

6. Your rights (GDPR / CCPA)
Depending on where you live: access, rectification, erasure, restriction, portability,
objection, withdraw consent, lodge a complaint with your DPA.

To exercise any right, email privacy@calccircuit.com. We respond within 30 days.

7. Children's privacy
Service not directed to children under 13 (or 16 in the EEA). We do not knowingly collect
data from children. Contact us if a child has provided data and we will delete it.

8. Data retention
  - Analytics events: 90 days, then aggregated or deleted.
  - Newsletter subscriptions: until you unsubscribe.
  - Account & saved calculations: while active. Inactive accounts deleted after 24 months.
  - Server logs (Cloudflare): per Cloudflare's standard policies.

9. International data transfers
Our servers are in the United States (Cloudflare edge). By using the site you understand
your data may be transferred to and processed in the US.

10. Security
HTTPS everywhere, hashed session tokens, rate-limited APIs, Cloudflare edge security.

11. Changes to this policy
We may update this policy. The "Last updated" date will reflect the latest revision.
Material changes announced via the cookie banner and (for subscribers) by email.

12. Contact
  - Email: privacy@calccircuit.com
  - General: /contact
  - Postal: CalcCircuit, 548 Market St, San Francisco, CA 94104, USA