Ovulation Calculator

Try our advanced and accurate ovulation calculator for tracking of your menstrual cycle. Determine your ovulation date, identify your peak fertility days, learn when to take a pregnancy test, find out the expected date of your next period, and even estimate your due date if you conceive during these specific dates. Explore exciting features of this accurate ovulation calculator and advanced fertility calendar.

Select first day of your last period *

Frequently Asked Questions about Ovulation Calculator

How to use the advanced ovulation calculator & fertility calendar?

1. Begin by selecting the first day of your last menstrual period. Simply tap on the date in the calendar. You can navigate to the previous or next month using the > and < arrows.
2. Next, indicate the average length, or number of days, of your menstrual cycle.
3. Tap the blue 'CALCULATE' button to see the results.
4. For a thorough understanding of the results, we strongly recommend reviewing the FAQs below.

Are online ovulation calculators & fertility calendars accurate?

Many online ovulation calculators and fertility apps may provide inaccurate information. To test their accuracy, consider this example: For women with an average cycle of 28 days, most apps suggest fertile days between day 11 and 15 of the cycle. However, according to the "Standard Days Method" (SDM), a contraception method with a 95% effectiveness rate, days 8 to 19 of a woman's menstrual cycle are fertile for those with a cycle length between 26 to 32 days. This highlights the potential for missed opportunities for conception if relying on misleading apps.
Using our Ovulation Calculator with a 28-day cycle length, it calculates a fertile window of 10 days, starting from day 9 and extending to day 18 of your cycle. We've intentionally excluded days 8 and 19 due to their very low chances of conception, less than 2%. Our application strives for precision and accuracy.

What is a menstrual cycle?

A menstrual cycle is a natural, monthly process occurring in women of reproductive age. It involves a series of changes that prepare the body for potential pregnancy. If pregnancy doesn't occur, the uterine lining sheds, resulting in menstruation or a period. This cycle is measured from the start of one period to the beginning of the next, with an average duration of 28 days. However, menstrual cycles can vary, lasting anywhere from 21 to 35 days in adults and 21 to 45 days in young teenagers.

What happens during ovulation?

In the first phase of the menstrual cycle, estrogen levels rise, causing the uterine lining to thicken. Simultaneously, an egg or ovum in one of the ovaries begins maturing. Around day 14 of an average 28-day cycle, the mature egg is released in a process called ovulation. After release, the egg travels through the fallopian tube toward the uterus. Hormone levels rise, facilitating the preparation of the uterine lining for potential pregnancy. The period around ovulation, typically three days before or on the day of ovulation, presents the highest likelihood of conception. It's important to note that women with cycles shorter or longer than the average 28 days may experience ovulation before or after day 14. Pregnancy occurs if the egg is fertilized by a man's sperm and attaches to the uterine wall. In the absence of fertilization, hormone levels decrease, leading to the shedding of the thickened uterine lining during menstruation.

When does ovulation occur?

For most women, ovulation generally takes place in the middle of their menstrual cycle. However, the length of menstrual cycles can vary between women and even within the cycles of the same individual. Even among women with fairly regular cycles, the day of ovulation can fluctuate by ±3 days. Our calculator utilizes data from multiple studies to provide a range of days when ovulation is most likely to occur. Ovulation is most probable in the middle of this range, with lower chances at the beginning and end.

How does this advanced ovulation calculator & fertility calendar calculate the ovulation date?

Our tool predicts your probable ovulation day based on data from recent and reliable studies. The results consider your typical cycle length and the start date of your last period. In 50% of cases, ovulation is expected to occur within two days before or after the calculated date. Additionally, it provides a range for the start and end of your ovulation period, within which there is a 95% likelihood of ovulation.

What are fertile days?

Fertile days are the days during your menstrual cycle when having unprotected intercourse may result in pregnancy.

What is the difference between ovulation and fertile days?

Ovulation is the process of releasing an egg from an ovary, occurring 12-16 days before the next period. Fertile days refer to the days in a woman's menstrual cycle when she can become pregnant through unprotected intercourse.

What does high, medium, and low fertility mean?

"Low Fertility" indicates very low chances of pregnancy (about 2-4%) at the start of your fertile days.
The highest chances of getting pregnant occur around the middle of your fertile days, referred to as the "You'll be Most Fertile on" date in the report.
Following this date, the likelihood of ovulation and pregnancy gradually decreases.

Timing and frequency of intercourse for maximizing pregnancy chances?

Research suggests that more frequent intercourse increases the likelihood of conception in a cycle. Sperm stored in the testicles for extended periods may experience DNA damage, reducing fertility. Couples aiming to conceive are generally advised to have sex at least once every 2 to 3 days. For optimal results, engaging in intercourse every other day (preferably in the morning) during the entire fertile period is recommended.

Can we use ovulation calculator for boy or a girl?

Various theories claim that the timing of intercourse can influence the gender of your baby. However, these theories lack scientific evidence. Unless you use sperm-sorting techniques followed by artificial insemination, the odds of having a boy or girl are generally 50-50.

Can the advanced ovulation calculator help with conception?

Yes, ovulation calculators can assist in identifying the most fertile days, increasing the chances of conception when timed correctly.

How reliable is the ovulation calculator for irregular periods?

Ovulation calculators may be less accurate for women with irregular periods. Tracking additional signs of fertility or consulting a healthcare provider is recommended.

Can you use an ovulation calculator for contraception?

No, ovulation calculators are not reliable methods of contraception and should not be used as the sole means of preventing pregnancy.

Do ovulation calculators work for women with fertility issues?

While ovulation calculators can provide insights for women with fertility issues, consulting with a healthcare provider or fertility specialist is advisable for a more comprehensive evaluation.

Reviewed By

Dr Sobia Mohyuddin

MCPS, FCPS, MRCOG, Consultant Obstetrics & Gynaecology

Doctor Sobia Mohyuddin is a highly skilled and experienced Obstetrician and Gynecologist, with 25 years of training and experience in renowned, large institutions. She holds the position of Associate Professor and Fellow at the College of Physicians and Surgeons Pakistan. She is also a member of the Royal College of Obstetricians and Gynecologists (UK).