Work out when you are most fertile

Is your menstrual cycle regular? If it is, then you can easily calculate when you are most fertile. Ovulation occurs 14 days before the beginning of your period. The most fertile days are two to three days around the time of ovulation. However, if you have sexual intercourse up to five days preceding ovulation, this can still lead to fertilisation.

Work out when you are most fertile

Last period: the first day of your last period.

Average cycle: the average number of days of your cycle. The cycle starts on the first day of your period and ends the day before the following period.

The date shown will be more or less your ovulation day. This means that you are most fertile two or three days either side of this date.

Fill in the boxes to work out when you are most fertile.

The date of the beginning
of your last period:

The length of your average cycle:

days

Calculate