Our free Ovulation Calculator helps you accurately predict your most fertile window by using your last menstrual period (LMP) and average cycle length. Understand your body's cycle better to increase your chances of conception and plan your pregnancy journey effectively.
Formula:
The Ovulation Calculator estimates your ovulation date by subtracting 14 days (the typical luteal phase length) from your average cycle length, then adding this to your Last Menstrual Period (LMP) date.
- Ovulation Day = (LMP Date) + (Average Cycle Length - 14 days)
- Fertile Window Start = Ovulation Day - 5 days
- Fertile Window End = Ovulation Day + 1 day
Where:
- LMP Date: The first day of your last menstrual period.
- Average Cycle Length: The number of days from the start of one period to the start of the next (commonly 28 days).
- Luteal Phase: The period from ovulation to the start of the next period, typically 14 days.