Privacy Policy
Effective Date: October 24, 2026 • Aligned with Google Publisher Policies, GDPR, and CCPA
1. Overview & Offline-First Architecture
At convert-calculate (accessible from https://convert-calculate.com), the privacy and confidentiality of our visitors is of paramount importance. Our core computation engine is architected to perform unit conversions and multi-variable formula calculations entirely client-side within your browser. Your numerical inputs, custom equations, and laboratory values are never transmitted to our backend servers or stored externally.
2. Google AdSense & Third-Party Cookies
We use Google AdSense to display advertisements on selected public pages of our platform. Google's advertising policies require the following specific disclosures:
- Third-party vendors, including Google, use cookies to serve ads based on a user's prior visits to this website or other websites.
- Google's use of advertising cookies enables it and its partners to serve ads to our users based on their visit to our sites and/or other sites on the Internet.
- Users may opt out of personalized advertising by visiting Google Ads Settings ↗ or through AboutAds.info ↗.
Subscribers to our Plus, Pro, and Admin membership tiers experience a completely ad-free platform where third-party advertising scripts are suppressed.
3. Web Analytics (Google Analytics 4)
We use Google Analytics 4 (GA4) with IP anonymization enabled to analyze aggregate website traffic, page performance, and geographic visitor distribution. GA4 collects non-personally identifiable telemetry such as browser type, operating system, session duration, and page view sequences. This telemetry helps us optimize calculation performance and Core Web Vitals.
4. User Accounts & Firebase Authentication
When you create an account or sign in with Google:
- We authenticate your identity using Firebase Authentication via Google OAuth.
- We store your basic profile information (email address, display name, and membership tier) in Google Cloud Firestore to maintain your saved tools, Studio templates, and subscription entitlements.
- We do not sell, rent, or trade your personal information with third parties.
5. Payment Processing (Stripe)
Paid membership transactions are processed through Stripe, an industry-leading PCI-DSS Level 1 compliant payment processor. Convert-calculate never captures, views, or stores your credit card numbers, CVVs, or financial credentials. All payment transactions are handled securely through Stripe's encrypted checkout infrastructure.
6. LocalStorage & Progressive Web App (PWA) Caching
Our application utilizes browser localStorage to remember your theme preference (dark/light mode), ad-free entitlements, and offline cached formulas via our Service Worker (sw.js). This data remains stored locally on your device and can be cleared at any time through your browser settings.
7. Contact & Data Subject Inquiries
For questions regarding this privacy policy, data access requests, or account deletion, please contact our administrative team at: