Privacy Policy
Last updated: May 14, 2026
1. Introduction
Welcome to Percentage Calculator. This Privacy Policy explains how we handle your information when you use our free online calculator service.
2. Information We Collect
2.1 Information You Provide
Our calculator works entirely in your browser. We do not collect or store the numbers you enter into the calculator.
2.2 Automatically Collected Information
When you visit our website, we may collect:
- Your IP address (anonymized)
- Browser type and version
- Pages you visit on our site
- Time and date of your visit
- Time spent on pages
- Your preferred language
3. How We Use Information
We use the collected information to:
- Provide and maintain our calculator service
- Understand how visitors use our website
- Improve our service and user experience
- Remember your language preference
- Generate anonymous usage statistics
4. Cookies
We use minimal cookies to:
- Language preference: Remember your selected language
- Analytics: Understand website usage (anonymous)
- Advertising: Google AdSense uses cookies to serve relevant ads
You can disable cookies in your browser settings, but some features may not work properly.
5. Data Sharing
We do not sell, trade, or rent your personal information to third parties. We may share anonymous, aggregated statistics about our website usage.
6. Data Security
We implement reasonable security measures to protect against unauthorized access to any information we collect. However, no internet transmission is 100% secure.
7. Third-Party Services
We may use third-party services for:
- Web analytics (anonymous data only)
- Content delivery networks (CDN)
- Font services
Advertising
We use Google AdSense to display advertisements on our website. Google AdSense uses cookies and similar technologies to serve ads based on your prior visits to this website or other websites. Google may use advertising cookies to enable it and its partners to serve ads based on your visit to our site and/or other sites on the Internet.
You may opt out of personalized advertising by visiting Google Ads Settings at www.google.com/settings/ads. Alternatively, you can opt out of third-party vendor cookies by visiting the Network Advertising Initiative opt-out page at optout.networkadvertising.org.
These services may collect anonymous usage data according to their own privacy policies.
8. Newsletter Subscriptions
If you subscribe to our newsletter, we collect and store your email address solely for the purpose of sending you periodic updates and educational content related to our calculator service.
- We store your email address and the timestamp of your subscription.
- Every email contains an unsubscribe link. You can unsubscribe at any time, which removes your address from our list.
- We never sell, share, or rent your email address to third parties.
- Subscription requests are rate-limited by IP address (not stored long term) to prevent abuse.
9. Contact Form
When you submit a message via our contact form, we store your name, email address, message content, and the IP address from which the message was submitted. This data is used only to respond to your inquiry and to detect abuse.
- Messages are retained while we operate the service and may be deleted on request.
- We use Cloudflare Turnstile to verify that the form is submitted by a human. Turnstile may collect technical signals from your browser as described in Cloudflare's privacy policy.
10. Browser Extension
We publish a free Chrome browser extension that wraps the same calculators in a popup. The extension is privacy-first by design.
What stays on your device
- All calculations run locally in your browser. No numbers you enter are sent to our servers.
- Calculation history, pinned items and theme preference are stored in chrome.storage.local on your device.
- Numbers you dismiss from the on-page selection banner are remembered in chrome.storage.session and cleared when the browser restarts.
When the extension contacts our servers
- The extension may fetch a small JSON configuration file (less than 1 KB) from /api/extension-config to know whether to show an in-popup ad slot. This request includes only your IP address and standard browser headers.
- Clicking the "Full site" link opens our website in a new tab. The extension itself does not transmit your calculations.
In-popup ad slot
When enabled, the popup may render a small ad. Ad content is served only as structured fields (image URL, link, title, description) loaded from our own server — never as arbitrary HTML or scripts. Ad images are restricted to our domain. The extension does not load third-party tracking scripts and does not run ad networks inside the popup.
11. Children's Privacy
Our service is not directed to children under 13. We do not knowingly collect personal information from children.
12. Your Rights
You have the right to:
- Access any personal data we have about you
- Request deletion of your data
- Opt-out of analytics tracking
- Refuse cookies through your browser settings
13. Changes to This Policy
We may update this Privacy Policy from time to time. We will notify you of any changes by posting the new Privacy Policy on this page.
14. Contact Us
If you have any questions about this Privacy Policy, please contact us at:
Email: [email protected]