A woman's fertile days are based on ovulation and are calculated using the menstrual cycle and the last menstrual bleeding (period). Ovulation usually takes place 14 days after the last period. Fertile days often begin two days earlier.


First day of the last period:
Length of the cycle:

All information is without guarantee

Use calculator:

  • Enter the date of your last menstrual period.
  • Select the duration of your cycle or period.
  • Click on

Ovulation is an important moment in a woman's menstrual cycle when a mature egg is released from the ovary and is ready to be fertilized. Knowing the exact timing of ovulation can be invaluable for women trying to conceive or those using a natural method of contraception. With our online ovulation calculator, you can determine the likely timing of your ovulation based on the date of your last period and the length of your menstrual cycle.

How the calculation works:

In a typical menstrual cycle of 28 days, ovulation usually occurs about 14 days before the start of your next period. For women with a different cycle, this average is used for adjustment.

  1. Date of last period: Start by entering the first day of your last menstrual period into the calculator.
  2. Length of menstrual cycle: The length of the cycle varies from woman to woman. Some have cycles that last only 21 days, others can last up to 35 days or longer. Enter the average length of your cycle into the calculator.

With this information, the tool will calculate the likely period of your next ovulation.

Please note:

  • The date given by our calculator is an estimate. Many factors can affect the exact time of ovulation, including stress, illness or changes in routine.
  • A woman's fertile phase includes not only the day of ovulation itself, but also the days leading up to it. Sperm can survive for several days in the female reproductive system waiting for an egg.
  • If you are trying to get pregnant or want to avoid pregnancy, it is advisable to seek professional advice and support to closely monitor your menstrual cycle and ovulation.


Our online ovulation calculator is a helpful tool that allows women to better monitor and understand their cycle. It provides an estimated ovulation prediction based on individual cycle information. However, for detailed insights and accurate monitoring, a consultation with a healthcare professional is always advisable.

Our website does not offer medical advice. All information is therefore without guarantee.


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