Period Calculator (Next Period Date)
Period calculator: predict your next six periods and approximate ovulation days from the start of your last period and your cycle length.
next period = last start + cycle length
How to use this calculator
- Type your input in the box.
- The result updates as you type.
- Use “Copy result” or “Copy link” to share it.
Most cycles last 21–35 days. Ovulation happens about 14 days before the next period, not 14 days after the last one.
Irregular cycles make predictions less reliable.
For general information only; it does not replace advice from a doctor or other health professional.
Frequently asked questions
Last period November 1, 28-day cycle?
Next period around November 29.
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