Conception Calculator

The Conception Calculator assesses the conception windows and the corresponding due date based on your personal biological cycles. Conception is the initiation of pregnancy, or when an egg and sperm form a union. It normally occurs in the ampulla of the uterine tube. In vitro fertilization (IVF) is a process by which conception occurs outside the body. If conception occurs via sexual intercourse, sperm can normally live inside a woman for three to five days, or up to seven days. However, sperm mobility decreases after three days. The best time to get pregnant is during the three-day "window", or two days before to the ovulation day.


Most Probable
Conception Days
Best Intercourse DaysPossible
Conception Days
Due Date
06/22/2013 - 06/26/201306/20/2013 - 06/26/201306/20/2013 - 06/30/201303/18/2014
07/21/2013 - 07/25/201307/19/2013 - 07/25/201307/19/2013 - 07/29/201304/16/2014
08/19/2013 - 08/23/201308/17/2013 - 08/23/201308/17/2013 - 08/27/201305/15/2014
09/17/2013 - 09/21/201309/15/2013 - 09/21/201309/15/2013 - 09/25/201306/13/2014
10/16/2013 - 10/20/201310/14/2013 - 10/20/201310/14/2013 - 10/24/201307/12/2014
11/14/2013 - 11/18/201311/12/2013 - 11/18/201311/12/2013 - 11/22/201308/10/2014

The results of this calculator are estimation based on average.

First Day of Your Last Period:
Average Length of Cycles:

RelatedPregnancy Calculator | Pregnancy Conception Calculator

Understanding the Fertility Window

The "fertility window" is a scientific fact: You have a better chance of becoming pregnant during the three-day "window,", or two days before the ovulation day. But it's all part of a much bigger process.

Love and Childbearing

The desire to have a child is all about love, for your partner, and for the child you will watch grow up.

Deep as this desire is in most couples, life often gets in the way. We suffer stress and worry from our work; we have little time as we try to deal with the day-to-day distractions and chores. The result is, we do not find time or have the feeling for making love as much as we might like to.

Yet, the first thing to know when you are trying to have a baby is that regular sex with your partner is the best preparation of all. When you are trying to have a baby, you should make love regularly - at least 2 to 3 times a week - even when you do not necessarily believe you are fertile or are near your ovulation day.

Regular lovemaking prepares the woman's body for childbearing, and raises the hormonal level associated with it. Low fertility itself is directly associated with lowered feelings of sexuality. Lifestyle and relationships all enhance the chances of conception.

Regular lovemaking also creates more favorable conditions in the vagina. The presence of fertile-quality (or egg-white) cervical mucus fosters fertility. Moreover, the favorable vaginal conditions will assist in protecting the sperm and extending sperm life-span. In effect, fertile cervical fluids should extend the fertile window by creating a "sperm-friendly" environment in your vagina.

Making the Fertility Window Work for You

With a pattern of regular lovemaking achieved, the next thing to do is identify that handful of days directly prior to, and including the day of ovulation. Identifying this "window" will significantly boost your chances of conception.

This means tracking your personal biological cycle. One of the most effective ways to do this is with our conception calculator. Note the first day of your last period. Then note the length of the cycle to the next period. With those data, you can input the numbers into the calculator and get a list of the best days for intercourse and conception.

You can help the process along by keeping a basal body temperature chart. Tracking your basal body temperature and your cervical mucus can help you get pregnant. The patterns you see month after month can help you predict ovulation – and once you know when you're likely to ovulate, you can have sex (or plan insemination) at the best time for conceiving.

Your basal body temperature is the lowest body temperature in a 24-hour period. To get an accurate reading, you must take your temperature when you first wake up in the morning, before you even sit up in bed. And you'll need to use a basal thermometer (available at most pharmacies) which is sensitive enough to measure minute changes in body temperature. Try to wake up and take a reading at about the same time each morning.

Before ovulation, your basal body temperature will be in normal range – from about 97.2 degrees to about 97.7 degrees Fahrenheit. Two or three days after you ovulate, the temperature will rise by about one-half to one degree, and it will remain at that level until you have your period.

As for your cervical mucus, when your period is over, you'll most likely be dry for several days. After that, you'll start to have cloudy mucus that's a bit like sticky paste.

A few days before ovulation, the mucus will become clear and slippery, very much like raw egg white, and you'll have more of it. This lasts until the day of ovulation.

As you track these changes in both body temperature and cervical mucus, you'll begin to make out your own biological pattern. You'll know, more or less, when to expect these changes. Working with the calculator, and this tracking, you'll be able to vastly increase your chances of becoming pregnant.

If you've been keeping track for a few months and you find that you ovulate on a different day each month of the cycle, (for example, day 14, then day 17, then day 12), you need to make use of a combination of the signals. Perhaps your cervical mucus changes on a certain day before you ovulate. Or you note a particular change in temperature. A pattern of one type or another usually emerges if you track carefully and accurately.

Follow Your Feelings

Many women find the tracking process attractive, as a means to get closer to their own bodies.

But some women find the charting too stressful. With so many things to worry about in life, they may not care to add another.

If stress is an issue, experts say that you should just try to have sex every two days as a minimum. If you can keep that going, you have an excellent chance of hitting a day when your body conditions are favorable. Sperm live up to seven days in the woman's body, so increased contact can only work in your favor.

After all, feeling good and loving is an essential part of the process, and perhaps the most important part.