Privacy Policy

Information we collect

Calculator inputs. Our tools run entirely in your browser. The numbers you enter are never sent to our servers and we do not receive or store them unless we say otherwise on a specific page.

Data stored on your device. To remember your choices — for example display settings, cookie consent, calculator options, and whether you found a page helpful — we save small values in your browser's local storage. If you have not chosen units on a calculator before, we infer a default from your browser language and region; that also stays on your device. These values are not tracking identifiers and are not sent to us. Clearing your browser data removes them.

Usage data. Like most websites, we and our providers may collect technical information such as your IP address, browser type, device type, pages visited, referring page, and approximate location derived from your IP. We use this to operate and secure the site, understand traffic, and show ads.

Contact. If you email us, we receive the information you send (such as your email address and message).

Where it comes from. We collect this information from you directly when you contact us, and automatically from your browser and device when you visit the site. We do not buy personal information from data brokers or obtain it from other third-party sources.

Cookies and advertising

We use cookies and similar technologies for analytics and advertising. No analytics or advertising cookies are set until you accept them in our cookie banner — if you reject or ignore the banner, those scripts are never loaded.

Analytics. With your consent we use Google Analytics 4 to measure traffic (including optional page feedback such as whether a calculator was helpful), with IP anonymization enabled.

Advertising. We display ads through Google AdSense. Google and other ad partners may use cookies to serve and measure ads, including ads based on your visits to this and other sites. This policy covers that use.

You can manage cookies in your browser settings. To opt out of personalized ads from Google, visit Google Ads Settings. See Google's Privacy Policy for how Google uses data from partner sites.

Cookie preferences

You can change or withdraw your cookie choice at any time. Withdrawing consent stops analytics and advertising cookies from loading on future visits.

Your current choice: Loading…

Third-party links

Our site may link to other websites. We are not responsible for their privacy practices. Some pages may include affiliate links in the future; those will be disclosed on the page.

How we use and share information

We use collected information to run and improve the site, respond to messages, and comply with law. Where the GDPR applies, our legal basis is your consent for analytics and advertising cookies, and our legitimate interest in operating and securing the site for basic server logs.

We rely on a small number of providers who process data on our behalf: Cloudflare (hosting and content delivery, which keeps standard server logs) and Google (Google Analytics 4 and Google AdSense).

We do not sell your personal information for money. Note that under some US state privacy laws, including the California Consumer Privacy Act as amended, serving personalized ads can count as "sharing" personal information for cross-context behavioral advertising. You can opt out of this by rejecting cookies in our banner, using the cookie preferences control above, or adjusting Google Ads Settings. We also honor the Global Privacy Control signal where required.

Retention and international transfers

We keep data only as long as needed for the purpose it was collected. Google Analytics data is retained for a limited period set in our Google Analytics settings; hosting logs are kept for a short period for security and troubleshooting; emails you send us are kept as long as needed to handle your inquiry.

Our providers operate globally, so your information may be processed in countries outside your own, including the United States. Those providers use standard contractual clauses or equivalent safeguards for transfers out of the UK and European Economic Area.

Your choices

You can change or withdraw your cookie consent at any time using the cookie preferences control above, and manage cookies in your browser settings.

Depending on where you live, you may have rights to access, correct, or delete personal data we hold about you, to object to or restrict processing, to data portability, and to lodge a complaint with your local data protection authority. To make a request, contact us at [email protected].

We will not discriminate against you for exercising any of these rights. Every calculator on this site stays free and fully functional whether you accept cookies, reject them, or ask us to delete your data.

Children

The site is intended for a general audience. We do not knowingly collect personal information from children under 13. If you believe a child has provided us information, contact us and we will delete it.

Changes

We may update this policy from time to time. When we do, we revise the "last updated" date at the top of this page. If a change materially affects how we use cookies or handle your data, we will reset your cookie choice so the banner asks you again rather than relying on your earlier answer.

Contact

Questions: [email protected] or our contact page.