The short version

The calculators on this site run entirely in your browser. We don't send your inputs (dimensions, units, calculations) to any server, and we don't store them. To keep the site free, we use Google Analytics to understand traffic, and we show ads through Google AdSense and Adsterra. Those services may set cookies and process limited information about your visit, as described below.

What we collect directly

Nothing about your calculations. Your inputs and results are computed in your browser and stay there. If you share a calculation by URL (e.g. ?l=30&w=20&h=15), that data lives in the link itself — not on our servers.

We don't ask for accounts, names, or email addresses. We don't operate a login system.

Third-party services

Google Analytics

We use Google Analytics 4 to measure traffic and understand which pages and tools are useful. Google Analytics collects:

• Pages you visit on this site and the order you visit them
• Time spent on each page
• Approximate location (typically city-level), derived from your IP address
• Device type, browser, operating system
• Referring website (where you came from)

Google Analytics may set cookies in your browser. See Google's privacy policy and how Google Analytics handles data for details. You can install the Google Analytics opt-out browser add-on to opt out of all Google Analytics tracking.

Google AdSense / Google Ads

We display advertisements through Google AdSense to support the site. Google AdSense uses cookies and similar technologies to:

• Serve ads based on prior visits to this and other websites
• Measure ad performance
• Prevent the same ad from being shown too often

You can opt out of personalized advertising by visiting Google's Ad Settings. For more information about Google's use of cookies for advertising, see Google's advertising privacy policy.

Adsterra

We also use Adsterra as an advertising partner. Adsterra and its advertising partners may use cookies and similar technologies to deliver and measure ads. For more information about Adsterra's data practices and to opt out, see Adsterra's privacy policy.

Cookies

The cookies on this site come from the third-party services above (Google Analytics, Google AdSense, Adsterra). We don't set first-party cookies for our own purposes. Cookies set by our partners are governed by their respective privacy policies.

You can manage or disable cookies through your browser settings. Disabling cookies will not affect the calculator functionality, since the calculators run in your browser and don't depend on cookies.

Embedded calculator (iframe)

If you embed our calculator on your own site via the embed widget, the same rules apply: calculations happen in the visitor's browser, and Google Analytics / ad partners may load. Be sure to mention this in your own site's privacy policy if you embed our widget.

Your rights (GDPR / CCPA)

If you're in the European Economic Area, the United Kingdom, or California, you have rights regarding personal data collected about you. Because we collect almost nothing ourselves, most requests will involve our advertising and analytics partners directly:

• Access / deletion of analytics data: Use the Google Analytics opt-out tool linked above, or contact Google directly.
• Opt out of personalized ads: Use Google's Ad Settings and YourAdChoices.
• "Do Not Sell My Personal Information" (CCPA): We do not sell personal information. Our ad partners may share data with their networks; use their opt-out tools to limit this.

To contact us about any privacy concern, see the contact information on the about page.

Children

This site is not directed at children under 13. We do not knowingly collect personal information from children.

Changes to this policy

If we change this policy, we'll update the date at the top of this page. For material changes, we'll add a notice on the site for a reasonable period.