Terms of use

By using this site you agree to the terms below.

Written by the Online Period Calculator editorial teamPublished 2026-08-19Updated 2026-08-19

Educational use

All tools and content on this site provide estimates for personal planning and education. They are not medical advice, diagnosis or treatment, and must not be used as contraception or as a substitute for consultation with a licensed clinician.

Acceptable use

You may link to and embed our tools with attribution. You may not scrape, misrepresent, or redistribute the site in a way that implies medical endorsement or that removes attribution.

No warranty; limitation of liability

Predictions are estimates that depend on the accuracy of your inputs and your cycle regularity. The site is provided "as is" without warranties of any kind. To the maximum extent permitted by law, we are not liable for decisions made on the basis of these estimates.

Changes

We may update these terms; the date below reflects the current version. Continued use after changes constitutes acceptance. Questions: contact@onlineperiodcalculator.com.

This tool provides estimates for personal planning only and is not a substitute for professional medical advice, diagnosis or treatment. Predictions must not be used as contraception. If you have concerns about your cycle, heavy bleeding, severe pain or missed periods, please consult a licensed clinician.