Terms of Service

1. The service

Sleep Calculator ("we", "us", "the site") is a free online tool that estimates bedtimes, wake-up times and nap lengths using an average 90-minute sleep-cycle model. Everything runs in your browser, no account is needed, and the service is provided free of charge on an "as is" and "as available" basis. We may add, change or withdraw features and pages at any time without notice.

2. Not medical advice, no warranty

The times shown on this site are general-information estimates built on population averages. They are not medical advice, not a diagnosis and not a treatment plan; individual sleep needs vary widely. If you have insomnia, suspect a sleep disorder, or have any health concern, consult a qualified physician — and never delay or ignore professional advice because of something you read here.

We make no warranty of any kind, express or implied, about the accuracy, availability or fitness of the site for a particular purpose. To the maximum extent permitted by law, we are not liable for any loss or damage arising from reliance on the site's results or from any interruption or error in the service.

3. Permitted and prohibited use

You may use the calculators for personal, educational and internal business purposes, and you are welcome to link to any page. You must not: (a) scrape, harvest or bulk-download the site's content; (b) republish substantial parts of the site as your own work; (c) attempt to disrupt, overload or probe the site or its hosting infrastructure; (d) use the site for any unlawful purpose; or (e) embed or frame the site in a way that hides or alters its advertising or attribution.

4. Intellectual property

The site's original text, page design and code are owned by Sleep Calculator and protected by copyright. The general concept of 90-minute sleep cycles is public scientific knowledge and is not claimed. Short quotations accompanied by a link back to the source page are welcome.

5. Advertising and third-party services

The site is funded by third-party advertising, including Google AdSense. Advertisers, not Sleep Calculator, are responsible for the content of their ads and for any website an ad links to. Details of cookies, consent and data processing are set out in our Privacy & Cookie Policy, which forms part of these terms.

6. Changes to these terms

We may revise these terms from time to time — for example when we add features or when the law changes. The current version, with its effective date, is always published on this page. Continued use of the site after a change means you accept the revised terms.

7. Termination

We may suspend or block access to the site, entirely or for specific users, networks or automated clients, if we believe these terms are being violated or to protect the service. Because the site requires no account, you can stop using it at any time with nothing further required from you.

8. Contact

Questions about these terms: [email protected] · General enquiries: contact page · Privacy questions: see the Privacy & Cookie Policy.