Terms of use

By using Calclens you accept these terms. They explain what we provide, what we don’t, and how to use the site responsibly.

These terms apply to calclens.com and any subdomains we operate. By accessing, browsing, or using the site, you confirm that you’ve read and agree to them. If you don’t agree, please don’t use the site.

Who we are

Calclens is an independent UK project providing free online calculators with optional AI-generated explanations. Throughout these terms, “we”, “us”, and “our” refer to the operator of Calclens, contactable at [email protected]. “You” and “your” refer to anyone using the site.

What we provide

Calclens provides:

• Free, instant calculators that run in your browser
• Optional AI-generated explanations of calculator results, produced on demand
• Written guides, examples, and frequently asked questions for each calculator
• In future, optional paid PDF reports for selected calculators (separate terms will apply)

The site is provided free of charge for personal, non-commercial use. We may add, remove, or change calculators at any time.

Not professional advice

Specifically, nothing on Calclens should be relied on as:

• Financial or investment advice — for decisions about mortgages, loans, pensions, investments, or savings, please speak to an FCA-authorised financial adviser
• Medical advice or diagnosis — for health-related decisions, please consult your GP, NHS, or a qualified healthcare professional
• Tax or accounting advice — for decisions about tax, payroll, or business accounts, please consult a chartered accountant or HMRC directly
• Legal advice — for any legal matter, please consult a qualified solicitor

The numbers and explanations on Calclens are designed to help you think — not to make decisions on your behalf.

Accuracy and limitations

We work hard to keep our calculators accurate. Each formula is sourced from authoritative references (see our sources page) and tested before publication. However:

• Rates, thresholds, and rules can change, and there may be a delay before we update a calculator
• The calculators apply general formulas; your specific circumstances may produce a different real-world result
• AI-generated explanations are produced by a language model and may occasionally contain errors or oversimplifications
• We do not guarantee that the site will be available, error-free, or uninterrupted at all times

You are responsible for verifying any result before acting on it. If a number from Calclens disagrees with an official source (HMRC, NHS, FCA, your bank, your accountant), trust the official source and please tell us so we can investigate.

Acceptable use

You may:

• Use any calculator on Calclens for personal, educational, or non-commercial purposes
• Link to Calclens pages from your own website, blog, or social media
• Quote short excerpts from our explanatory content with proper attribution
• Take screenshots of calculator results for personal use

You may not:

• Scrape, crawl, or systematically download our content beyond what is reasonable for a human user
• Republish Calclens content (calculators, explanations, AI prompts) on another website without our written permission
• Embed Calclens calculators on another website (this feature is planned for a future release; until then, please link out instead)
• Attempt to bypass rate limits, access the API directly, or impersonate our service
• Use the AI feature to generate content that is illegal, harassing, defamatory, or that violates anyone else’s rights
• Reverse-engineer, decompile, or attempt to extract source code from the site beyond what is necessary for normal browser-side use

We reserve the right to block access from any IP address or visitor who breaks these rules.

Intellectual property

The Calclens name, logo, brand, written content, layout, and AI prompts are owned by the operator of Calclens. The calculation formulas themselves are not owned by us — they come from public sources listed on our sources page.

Some third-party libraries used to build the site are open source and remain under their original licences.

If you’d like to use Calclens content beyond the “acceptable use” rules above, please email [email protected] to discuss.

Third-party links

Pages on Calclens link to external websites — for example, government sources on the sources page, or Anthropic’s documentation on the how AI works page. We have no control over those websites and are not responsible for their content, privacy practices, or availability. Linking to a third party does not imply endorsement.

Liability

To the fullest extent permitted by UK law, Calclens and its operator are not liable for:

• Any direct or indirect financial loss, lost profits, or lost savings arising from the use of, or inability to use, this site
• Any harm, loss, or damage arising from a decision made wholly or partly on the basis of a Calclens calculation or AI explanation
• Any error, omission, inaccuracy, or interruption in the site’s content or service

Nothing in these terms limits liability for death, personal injury caused by negligence, fraud, or any liability that cannot be excluded under UK law.

Changes to these terms

We may update these terms from time to time. The current version is always the one on this page, and the date at the bottom shows when it was last changed. Material changes will be noted on the page; minor edits (typos, clarity improvements) may not be.

By continuing to use Calclens after a change, you accept the updated terms.

Governing law

These terms are governed by the law of England and Wales. Any dispute relating to Calclens or these terms will be subject to the exclusive jurisdiction of the courts of England and Wales, unless mandatory consumer-protection rules in your country of residence apply.

Contact

For any questions about these terms, please email [email protected] or use the contact page.

Last updated: May 2026