Ovulation Calculator: How to Calculate & When to Get Pregnant

Updated in January 2024

The ovulation calculator is a simple and quick way to determine when your fertile period. Having sex during this time increases the chance for a viable pregnancy.

Ovulation is characterized by the moment in the menstrual cycle in which an egg is released by an ovary. Fertilization during this time, known as the fertile window, marks the beginning of pregnancy.

To find out what day your next ovulation will be, enter the data into the calculator:


How is it calculated? 

The ovulation day occurs in the middle of the menstrual cycle, and therefore it is easier to calculate in women with regular cycle. If a woman has a 28-day cycle, for example, ovulation will occur at about the 14th day of the cycle. The first day of a cycle is the first day of your period, and ovulation will occur about 14 days later. 

The ovulation day can vary by 1 or 2 days with each cycle, and therefore women are generally advised to consider their fertile window instead of their ovulation day. The fertile window is a series of about 6 days in the cycle that occur around the ovulation day. Following a fertile window may be more accurate than following just the ovulation date, as it can compensate for ovulation that occurs a day early or a day late. 

In women with an irregular cycle, it is not possible to calculate the exact ovulation date, and knowing your fertile window can be more beneficial. Learn how to calculate your fertile window when your cycle is irregular. 

Possible symptoms

Ovulation can generate some characteristic symptoms which include: 

  • Transparent and sticky vaginal discharge, similar to egg whites 
  • A slight increase in body temperature, by about 0.5ºC or about 1ºF
  • Increased libido and appetite 
  • Possible pelvic pain, like a light cramping

Many women are unaware that these symptoms even occur, which is why they can be difficult to identify. Therefore, the best way for a woman to know she is ovulating is to calculate when her next ovulation date is. Learn more about the common symptoms that occur during ovulation.

It’s important to remember that women who take birth control do not ovulate, and therefore they do not present with any symptoms and are unable to get pregnant. 

Are ovulation and the fertile window the same thing?

Although these terms are often used interchangeably, ovulation and the fertile window are not the same. Ovulation is the day in which a mature egg is released by the ovary in preparation to be fertilized. The fertile window is a series of consecutive days that are calculated around the possible ovulation date. The fertile window defines a woman’s highest chance for pregnancy, as this period captures the release of an egg. A fertile window does not occur without ovulation. Calculate when your fertile window will occur.

When is the best time to get pregnant? 

The best time to get pregnant is referred to as the fertile window, and occurs in the 3 days before and the 3 days after ovulation. That is, it occurs between about the 11th and 16th day of a menstrual cycle. Women who are aiming to get pregnant should have unprotected sex during this period. Women who are trying to prevent pregnancy should be careful and avoid unprotected sex during this time.