Cycle Day Calculator
Find which day of your cycle today is, counting the first day of bleeding as day 1.
Your result
Day 1 is the first day of full bleeding. Ovulation usually happens around two weeks before the next period, which is why cycle length matters.
Medical disclaimer: This tool is for education and is not medical advice. Read more.
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Frequently asked questions
What does the Cycle Day Calculator do?
Find which day of your cycle today is, counting the first day of bleeding as day 1. Enter your values and the result and chart update instantly.
How accurate is it?
It uses published, widely used formulas. Results are estimates for education and planning, not a diagnosis. Talk to a qualified clinician about decisions affecting your health.
Is my information stored or shared?
No. All calculations run in your browser and nothing you type is sent to a server or saved.
What can I search to find this tool?
People find it by searching for: what cycle day am i on; cycle day counter; menstrual day count.