Privacy policy

sellmath (sellmath.com, "the site") is operated by an individual developer in South Korea. This policy explains what information the site handles and how.

1. Information you enter

The site has no accounts and no login. Numbers you type into a calculator (prices, costs, weights) are processed in your browser and are not sent to or stored on any server. To make results reopen, inputs are kept in your browser's local storage on your own device; you can clear them with the "Reset" button or by clearing site data in your browser.

2. Information collected automatically

• Hosting logs: the site is hosted on Cloudflare Pages. Cloudflare may process IP address, time of access, browser type and similar connection data to operate and secure the service, under Cloudflare's privacy policy. The operator does not use this data to identify individuals.
• Analytics: the site may use privacy-focused Cloudflare Web Analytics (no cookies) and/or Google Analytics to understand which pages are used. Google Analytics uses cookies to collect anonymous, aggregated usage data under Google's privacy policy.
• Advertising cookies: if Google AdSense ads are shown, Google and its partners may use cookies (including the DoubleClick cookie) to serve ads based on your visits to this and other sites. You can opt out of personalised advertising at Google Ads Settings or aboutads.info. Visitors in the EEA, UK and Switzerland will be asked for consent before such cookies are set.

3. Contact form

If you use the contact form, the name (optional), email (optional) and message you enter are forwarded to the operator's messaging app (Telegram) solely to answer you. They are not stored in a database on the site. Your country and IP address, as provided by the hosting platform, are included to filter spam. Messages are deleted after the matter is handled, or immediately on request.

4. International transfers

The services above (Cloudflare, Google, Telegram) operate servers in the United States and other countries, so the data described in sections 2 and 3 is processed outside your country. Each provider applies its own safeguards (such as standard contractual clauses for EEA data).

5. Your rights

Depending on where you live (for example under the GDPR in the EEA/UK or the CCPA/CPRA in California) you may have the right to access, correct or delete personal data, to object to processing and to opt out of the sale or sharing of personal information. The site does not sell personal information. Because the site itself stores nothing about you, requests usually concern the contact-form messages or third-party cookies; write to us through the contact form and we will respond within 30 days. You can also manage cookies in your browser settings; refusing cookies does not affect the calculators.

6. Children

The site is not directed at children under 16 and does not knowingly collect their data.

7. Changes

Changes to this policy are posted on this page with the date below.