Plain-English privacy policy. The short version: the percentage calculator runs entirely in your browser — your inputs are never sent anywhere. We do use Google Analytics, Google AdSense, and an Adsterra banner to keep the site free, and those services set cookies and collect standard browsing data. Details, opt-outs, and the things we’ll never do are all below.
The percentage calculator and all the specialty tools on this site run entirely in your browser. The numbers you type, the calculations you perform, and the results displayed are processed locally in JavaScript and are never sent to our servers — this is true even though we serve ads and use analytics, because those services have no access to what you type into the tool. We don’t sell your personal data. You can opt out of analytics and personalized ads with the steps below.
The following information never leaves your device, period:
You can verify this yourself: open your browser’s Network panel (F12 → Network), perform a calculation, and confirm there are no outbound requests carrying your inputs. The advertising and analytics scripts make their own network requests on page load, but those requests do not include your calculator inputs.
Like any web host, our server receives basic HTTP request data when you visit a page: your IP address, the URL you requested, the time, your browser’s user-agent string, and the referring page. This is used to deliver pages and to debug operational issues. Standard web-host access logs are retained for up to 30 days and then automatically deleted.
We use Google Analytics 4 to understand which pages are popular, which devices and browsers visitors use, which countries they come from, and roughly how long they spend on each page. This helps us decide what to build next and what content to improve.
Google Analytics sets cookies (typically named _ga and _ga_*) and collects:
Google Analytics does not receive: the numbers you enter into calculators, your real name, email, or any directly-identifying information. Google’s data-processing terms apply; see the Google Privacy Policy for full detail.
How to opt out of Google Analytics:
We display a banner ad served by Adsterra, an independent ad network. The Adsterra script may set its own cookies and collect standard ad-serving telemetry (impressions, clicks, viewability metrics, IP address, user-agent). Adsterra states it does not collect personally identifiable information; for their full disclosure see the Adsterra Privacy Policy.
The Adsterra ad slot is the rectangular advertisement banner just below the top navigation. The ad script is independent of the calculator tool — Adsterra does not see what you type into the calculator.
The cookies set by this site come entirely from the third-party services above. We do not set any first-party cookies of our own. The typical cookie list:
_ga, _ga_* — Google Analytics, ~2 yearspc_theme — set by our own site to remember your dark-mode preference. First-party, no tracking purpose, never sent off-deviceYou can clear these cookies anytime from your browser’s settings, or block them upfront with the privacy tools mentioned above.
The site uses your browser’s localStorage for one purpose: remembering whether you prefer light or dark mode (key pc_theme). This stays on your device and is never transmitted. You can clear it from your browser’s site-data settings.
Beyond analytics and ads, we load fonts from Google Fonts (fonts.googleapis.com) so the site renders consistently. Google’s font servers see your IP address and user-agent until the browser caches the fonts locally, but receive no other identifying information. The site falls back to system fonts if Google Fonts are blocked.
The site is general-purpose and not directed at children under 13. We don’t knowingly collect personal information from anyone under 13. The advertising partners listed above operate under their own age-verification and consent frameworks.
If you’re in the EU, EEA, UK, or Switzerland, you have the right to access, correct, delete, or export any personal data we hold about you, and to object to or restrict its processing. Since we don’t hold a database of users (just aggregate Google Analytics data and ad-network records held by Google and Adsterra), most requests are best directed to those providers using their own privacy interfaces. For anything else, email us at the address below and we’ll respond within 30 days.
California residents have the right to know what personal information is collected, to request its deletion, and to opt out of its “sale” or “sharing” for cross-context behavioral advertising. The Adsterra banner on this site may qualify as “sharing” under CCPA. You can exercise the opt-out by enabling your browser’s Global Privacy Control (GPC) signal (which we honor), by using a browser-level ad-blocker, or by emailing us directly at the address below.
If this policy changes materially, the updated version will appear at this URL with a new “Last updated” date. Substantive changes (anything that affects what data we collect or how) will also be flagged at the top of the homepage for at least 30 days.
Privacy questions, opt-out requests, or data-access inquiries: contactus@bestpercentagecalculator.net.
Last updated May 17, 2026. Questions? Email contactus@bestpercentagecalculator.net.