Estimate your fertility window with our easy-to-use ovulation calculator
If you’re trying to fall pregnant, the timing of when you and your partner have intercourse is critical.
Your fertile window refers to the most fertile days in your menstrual cycle which give you the highest chance of conceiving.
If you are trying to fall pregnant, the timing of when you and your partner have sex is critical. Melbourne IVF's online ovulation calculator can help you understand your fertile window or your window of opportunity to fall pregnant during an average menstrual cycle. You should be having sex every couple of days during your fertile window to maximise your chance of getting pregnant.
For our Ovulation Calculator to be the most accurate and useful, you’ll need to keep track of the dates of your recent menstrual periods.
Your cycle length is the number of days between the first day of bleeding of one period, and the first day of bleeding of the next. A woman's menstrual cycle can vary from 23 to 35 days, and 28 days is about average. If you have irregular menstrual cycles, calculating your ovulation date can be more difficult, but we suggest going by your shortest period date to ensure you don’t miss your ovulation date. Ovulation urine tests can give you some idea of your fertility window, or you might find further advice from your GP or fertility specialist useful.
How to use our Ovulation Calculator
Simply select your usual cycle length from the dropdown box and then choose the date on the calendar when your last period started. With this information, our ovulation calculator estimates your next fertility window (and the next one after that).
Based on your results from our ovulation calculator, you can also sign up for handy email reminders, so you’ll know your ‘Fertile Window' for the next few months.
How to calculate your fertile window / How to calculate ovulation
To calculate your fertile window, you need to determine what day you ovulate. To do this, you need to know the length of your menstrual cycle (which tends to vary from 23 to 35 days).
The length of your menstrual cycle is the number of days from the first day of bleeding in your last period to the first day of bleeding in your next. From this figure, subtract 14 days from the end of your current cycle to determine the approximate day you ovulate.
What if I have irregular menstrual cycles?
If you have irregular menstrual cycles, or your cycle length varies from month to month, it can be difficult to calculate your ovulation date. Ovulation urine tests or ovulation tracking may be useful, and you should consider seeking further advice from your GP or a Fertility Specialist.
When am I most fertile?
If you are trying to fall pregnant, the timing of when you and your partner have intercourse is important. The most fertile time in your cycle are the days leading up to ovulation, just before the egg is released from the ovary when the cervical mucus allows sperm to pass through the cervix and into the uterus and fallopian tubes. Sperm has the ability to live for 2–3 days in the cervix, uterus and tubes awaiting arrival of the egg. The egg is able to be fertilised in the 24 hours after release from the ovary.
To optimise your chances of conceiving, it is therefore recommended you have unprotected intercourse every two to three days in the lead up to ovulation. If you wait until you have ovulated before you have intercourse, it is most likely that you will have missed the opportunity for conception that month
How long should I try for, before seeking specialist advice?
It is recommended that you consider seeking professional advice after trying to conceive naturally without success for 12 months if you are under 35 years-old or after 6 months if you are over 35.
A fertility specialist can conduct some simple fertility tests to find out what’s happening, explore all your options and help you fall pregnant sooner.
Health advice if you are trying to conceive
There are three important ways you can improve your chances of falling pregnant naturally:
1. Understand your pregnancy window, and determine the best time in your cycle to have intercourse.
You can begin by using our Ovulation Calculator tool on this page.
2. Improve your health, diet and lifestyle – for both partners:
For both the male and female, it is time to commit to a healthy lifestyle:
- Quit smoking and any recreational drug use.
- Optimise your weight for a healthy BMI.
- Review your diet and alcohol intake, and reduce if necessary.
- And ensure you exercise regularly.
3. See a GP to ensure you are (both) in good health.
If you are trying to conceive, we recommend you and your partner get checked by your GP to ensure you are in good physical health. This typically involves blood tests to help with a review of your general health and a check of your current medications. For women your doctor will likely make sure you are up-to-date on your pap smear tests, rubella vaccine and advise you to start taking folic acid.
Learn more about preparing your body for pregnancy »
For a naturally conceived pregnancy to occur it requires normal egg production (ovulation) by the ovaries, normal healthy sperm both in structure (shape or morphology) and the ability to swim (motility), and normal fallopian tubes and uterus.
During intercourse the sperm will make their way through the woman's cervix into the uterus and then along the fallopian tubes. This is where the sperm will encounter an egg that has been released from the female ovary. Conception starts at the moment of fertilisation when a sperm penetrates the outer shell of the egg and an embryo is subsequently formed.
Over the next four to six days the embryo moves down the fallopian tube to the uterus and implants in the lining of the uterus where it will hopefully continue to grow.
Fertile Minds YouTube Channel
Watch helpful videos on all things fertility, from how to track your cycle and the best time to have sex to conceive, to gaining knowledge about female fertility factors such as endometriosis, fibroids and PCOS. Check out the Fertile Minds playlist here.