Zoe+Ruth Fertility Calculator
A woman's menstrual cycle lasts between 28 and 32 days on average. The beginning of each cycle is considered to be the first day of her menstrual period (menses). Ovulation itself generally occurs between day 10 and day 19 of the menstrual cycle, or 12 to 16 days before the next period is due.
This calendar should be used as a guide only.*
It’s a good idea to talk to your healthcare professional about trying to conceive. They can advise you on important areas like tests that may be required, current medications you may be taking and vaccinations that are recommended when planning pregnancy. They can also help you take into consideration any important information from your family medical history. If you are taking contraception, ask about advice before discontinuing use.
What is ovulation?
Ovulation is when a mature egg is released from the ovary, moves down the fallopian tube, and is available in the fallopian tube to be fertilised.
Tracking your ovulation
Work out the length of your average menstrual cycle. Day one is the first day of the menstrual period and the last day is the day before the next period begins. Ovulation happens about two weeks before the next expected period. So if your average menstrual cycle is 28 days, you ovulate around day 14. Remember the ‘fertile window’ is the six days leading up to and including ovulation.
The three days leading up to and including ovulation are the most fertile. Depending on your cycle length the most fertile days in the cycle varies:
If you have 28 days between periods ovulation typically happens on day 14, and the most fertile days are days 12, 13, and 14.
If you have longer cycles, say 35 days between periods, ovulation happens on day 21 and the most fertile days are days 19, 20 and 21.
If you have shorter cycles, say 21 days between periods, ovulation happens on day 7 and the most fertile days are days 5, 6, and 7.
It’s a good idea to talk to your healthcare professional about trying to conceive. They can advise you on important areas like tests that may be required, current medications you may be taking and vaccinations that are recommended when planning pregnancy. They can also help you take into consideration any important information from your family medical history. If you are taking contraception, ask about advice before discontinuing use.
What is ovulation?
Ovulation is when a mature egg is released from the ovary, moves down the fallopian tube, and is available in the fallopian tube to be fertilised.
Tracking your ovulation
Work out the length of your average menstrual cycle. Day one is the first day of the menstrual period and the last day is the day before the next period begins. Ovulation happens about two weeks before the next expected period. So if your average menstrual cycle is 28 days, you ovulate around day 14. Remember the ‘fertile window’ is the six days leading up to and including ovulation.
The three days leading up to and including ovulation are the most fertile. Depending on your cycle length the most fertile days in the cycle varies:
If you have 28 days between periods ovulation typically happens on day 14, and the most fertile days are days 12, 13, and 14.
If you have longer cycles, say 35 days between periods, ovulation happens on day 21 and the most fertile days are days 19, 20 and 21.
If you have shorter cycles, say 21 days between periods, ovulation happens on day 7 and the most fertile days are days 5, 6, and 7.
*This tool is totally free to use and needs no subscription, we suggest you use as a guide only. We do encourage you to also track and use the Basal Body Temperature (BBT) method, this will give you an even better indication of your exact days of ovulation for pregnancy planning (click here to go to the BBT information and downloadable FREE chart). All information on this page is not recorded or stored in any way by Zoe+Ruth.
Philipa @ Zoe+Ruth
Philipa @ Zoe+Ruth