Pms Cycle Calculator
Track and predict your menstrual cycle, ovulation period, and fertile window based on your cycle length and last period date.
Published by:
isCalculator Editorial Team
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How to use this tool?
How to Use the PMS Cycle Calculator
- Enter your last period start date – Click the date field and select the first day of your most recent menstrual period.
- Set your average cycle length – The number of days from one period start to the next (default 28, range 20–45).
- Enter your period length – How many days your bleeding typically lasts (default 5, range 1–10).
- Adjust your luteal phase length – The days between ovulation and your next period (default 14, range 10–16).
- Click "Calculate Cycle" – The tool will instantly show your predicted:
- Next period start and end dates
- Ovulation date
- Fertile window (5 days before ovulation + ovulation day)
Note: All dates are based on the inputs you provide. For accurate predictions, use your average cycle length and luteal phase length (consult your health provider if unsure). The calculator assumes ovulation occurs on day cycle length − luteal phase length.
Previous Results
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Frequently Asked Questions
Ovulation date is calculated by subtracting the luteal phase length from your average cycle length. For a 28-day cycle with a 14-day luteal phase, ovulation occurs on day 14.
The fertile window includes the 5 days before ovulation and the day of ovulation itself. This is the period when pregnancy is most likely to occur.
This calculator assumes a regular cycle. For irregular cycles, predictions may be less accurate. Consult a healthcare provider for personalized advice.
