Contact us
We read everything sent to contact@onlineperiodcalculator.com.
Corrections and questions
Spotted an error in a guide or a result that looks wrong? Tell us the page URL and what you expected — corrections are logged and published per our editorial policy.
Press and partnerships
For interviews, data requests or embedding our calculators in your product or clinic's resources, write to the same address with "Press" or "Partnership" in the subject line.
A note on medical questions
We cannot answer personal medical questions by email. If you are worried about your cycle, bleeding or pain, please contact a licensed clinician — that is the right channel, and we would be doing you a disservice by pretending otherwise.
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.