Ovulation calculator

Want to up your odds of getting pregnant faster? Here are some tips to try:

Ovulation Calculator

Based on the date of your last menstrual period and the length of your typical menstrual cycle, discover which days you’re most likely to be fertile and boost your chance of conceiving.

Medically Reviewed by Aaron Styer, M.D.

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on October 5, 2021

Latest update:

About This Tool

• When to try to get pregnant
• How we calculate your fertile window
• Ovulation symptoms
• Tips for getting pregnant

When to try to get pregnant

Trying to conceive? No one needs to tell you how to do it (leave the diagrams to the amateurs, thank you very much!), but you might need a little help figuring out when is the best time to have sex to get pregnant.

The short answer: The best time to conceive is around the time you ovulate. That prime “getting pregnant” window can include anywhere from a few days before ovulation — because sperm can live to fertilize for three to six days — until about a day after the release of the egg, which is only viable for about 12 to 24 hours.

How we calculate your fertile window

This ovulation calendar estimates when you will ovulate based on the date of your last menstrual cycle and the average number of days between your periods. First, we count back 14 days from the start date of your next expected period to calculate the date you’re most likely to ovulate. Then, we calculate your fertile window, which can extend a few days before ovulation and possibly up to one day after. Just note that this is not an exact science — menstrual cycles can vary from woman to woman and month to month (typical cycle length is anywhere between 21 and 35 days). And, if you have irregular periods, that might make it tougher to pinpoint your fertile window.

Ovulation symptoms

Wondering how to tell when you’re ovulating? Pay attention to these signs of ovulation:

• Your basal body temperature falls slightly, then rises again when ovulation has taken place.
• Your cervical mucus becomes clearer and thinner with a more slippery consistency similar to that of egg whites.
• Your cervix softens and opens up.
• You may feel a slight twinge of pain or mild cramps in your lower abdomen.
• Your sex drive may increase.
• You may notice some light spotting.
• Your vulva or vagina may appear swollen.

Tips for getting pregnant

Want to up your odds of getting pregnant faster? Here are some tips to try:

1. Take your prenatal vitamin

Start popping that prenatal at least a month before you begin trying for a baby. One study showed that women who were taking their prenatal vitamins while undergoing fertility treatments were twice as likely to get pregnant as those who were only taking a folic acid supplement while going through the same treatments. So while it’s not a guarantee that you’ll hit the baby jackpot sooner, it’s definitely worth a shot!

2. Know the signs of ovulation and time sex around it

Familiarize yourself with the typical ovulation symptoms to look out for and have sex starting a few days before you ovulate, which typically happens midway through your cycle (so on day 14 of a 28-day cycle). Having sex the actual day of ovulation would be ideal, but it can be hard to pinpoint it.

3. Eat well

Eating the right foods and nutrients when you’re trying to conceive can help your dreams of getting pregnant come true more quickly. Make sure you’re incorporating plenty of healthy fats like omega-3s, folate, calcium, protein, iron and fiber into your daily diet.

4. Exercise

Moderate exercise for 30 minutes a day has been shown to boost fertility, so now isn’t the time to turn into a couch potato. Whether it’s hitting the gym, going for a jog or lifting weights, try to fit in some kind of workout while you’re trying to conceive.

5. Don’t worry

Stress can delay ovulation, which in turn will get in the way of conception, and it has also been shown to increase the frequency of uterine contractions, so implantation will be more difficult. Try to find ways to relax: take a yoga class, soak in a bubble bath, go on a rejuvenating walk, write in a journal or get a massage.

6. Get enough sleep

Aim to log in seven to eight solid hours of sleep when you’re trying to conceive. Research has shown that spotty sleep has been linked to irregular periods, which can in turn hinder your fertility. Sleep is also important in staving off stress, which has also been found to hamper baby-making plans.

7. Cut out bad habits

If you smoke, it’s time to quit, as smoking has been shown to have a negative impact on fertility and getting pregnant. It’s also a good idea to stop drinking alcohol (or at least seriously limit your intake) while you’re trying to conceive and cut back your caffeine consumption to no more than 200 milligrams a day (about a 12-ounce cup of coffee).

View Sources

• What to Expect Before You’re Expecting, 2nd edition, Heidi Murkoff.
• What to Expect When You’re Expecting, 5th edition, Heidi Murkoff.
• WhatToExpect.com, Ovulation Symptoms, September 2020.
• WhatToExpect.com, Ovulation, 2021.
• WhatToExpect.com, Can You Get Pregnant on Your Period?, March 2021.
• WhatToExpect.com, Irregular Periods, September 2020.
• WhatToExpect.com, When Is the Best Time to Have Sex to Get Pregnant?, October 2020.
• WhatToExpect.com, Preparing for a Baby Before Conception, October 2020.
• WhatToExpect.com, How to Have a Boy or a Girl, March 2021.
• WhatToExpect.com, Prepregnancy Diet: Best Foods to Eat When You’re Trying to Get Pregnant, October 2020.
• WhatToExpect.com, How to Track Your Menstrual Cycle When You’re Trying to Get Pregnant, March 2019.
• WhatToExpect.com, Your Pregnancy Week-by-Week, June 2021.
• WhatToExpect.com, Preconception Health, 2021.
• WhatToExpect.com, Your Preconception Checkup, October 2020.
• WhatToExpect.com, How to Use Ovulation Test Strips to Predict Your Most Fertile Days, April 2020.
• WhatToExpect.com, How Do You Use a BBT Chart to Pinpoint Ovulation?, April 2020.
• University of Rochester Medical Center, Ovulation Date Calculator, 2020.
• Stanford Children’s Health, Ovulation Date Calculator, 2021.

Ovulation calculator

Knowing the days you are most likely to be fertile can increase your chance of getting pregnant. The typical menstrual cycle is 28 days long, but each woman is different. There are about 6 days during each menstrual cycle when you can get pregnant. This is called your fertile window. Use the calculator to see which days you are most likely to be fertile.

Fertile Window Ovulation Date

If your period starts:

If your menstrual cycle is:

Your estimated fertile window is:

Your estimated ovulation date is:

You are most likely to get pregnant if you have sex without birth control a few days before your ovulation date.

This ovulation calculator provides an estimate of your fertile window and is not a guarantee of pregnancy or of birth control. The calculator and information on this website are not medical advice. Talk to your doctor or nurse to plan for pregnancy and find birth control that works for you.

Fertile windows are different for every woman and can be different from month to month in the same woman. Learn more about your fertility if you are trying to get pregnant.

All material contained on these pages are free of copyright restrictions and maybe copied, reproduced, or duplicated without permission of the Office on Women’s Health in the U.S. Department of Health and Human Services. Citation of the source is appreciated.