Ovulation Calculator

Menstrual periods are different from woman to woman and month to month. Use this calculator to see when you may be ovulating to help find your most fertile days.

step 1

Select the first day of your last period

NOTE: This tool cannot and should not be used to prevent pregnancy. Results are estimates and actual ovulation will vary for each woman.

Signs of Ovulation

  • Rise in basal body temperature, typically 1/2 to 1 degree, measured by a thermometer
  • Higher levels of luteinizing hormone (LH), measured on a home ovulation kit
  • Cervical mucus, or vaginal discharge, may appear clearer, thinner, and stretchy, like raw egg whites
  • Breast tenderness
  • Bloating
  • Light spotting
  • Slight pain or cramping in your side

Pregnancy Tips

  1. Know when you ovulate:
    Ovulation usually happens 14 days before your next period begins, but it can vary from month to month -- even in women with regular cycles. To get a better sense of when you’re ovulating, chart your basal body temperature and your cervical mucus. Use an over-the-counter ovulation predictor kit or OPK, ovulation tracking bracelet, or lab tests to check for hormonal changes before ovulation.
  2. Have sex often:
    Your odds of getting pregnant are best when you have sex 1 to 2 days before you ovulate. But cycles vary in length, and some women are irregular or have miscalculated their cycle. Sperm can survive in a woman's body for up to 5 days. To hedge your bet, have sex frequently starting 3 days before ovulation and continuing for 2 to 3 days after you think you've ovulated.
  3. Lie low after sex?
    It has long been believed that you should stay in bed for at least 15 minutes after sex to give sperm a chance to reach the egg. However, recent studies found no evidence to back up this claim.
  4. Maintain a healthy weight:
    Studies show that weighing too little -- or too much -- may disrupt ovulation and affect production of key hormones. A healthy body mass index is between 18.5 and 24.9. Staying fit with moderate exercise is fine, but this isn’t the time to train for a marathon: Strenuous exercise can mess with your menstrual cycle, making it more difficult for you to conceive.
  5. De-stress:
    Research shows that stress may make it harder to get pregnant. Yoga, meditation, and long walks can help lower stress and improve your overall well-being.
  6. Manage medical conditions.
    If you have a medical condition such as diabetes, asthma, or epilepsy, be sure it is under control. Speak with your doctor about any prescription or over-the-counter medications you may be taking, since they might affect your chance of getting pregnant.
  7. His health matters, too.
    While it’s common to think of fertility as the woman’s responsibility, more than 33% of fertility issues involve only the man, and another 33% involve both partners as a couple. Like women, men can improve their reproductive health by quitting smoking, limiting alcohol, eating healthy, and lowering stress.
  8. Trying for a boy or a girl?
    Several theories claim you can influence the gender of your baby by having sex at a certain time of the month or in a specific position. However, there’s no surefire, natural way to choose the sex of your baby. Your odds are 50-50 unless you use a sperm-sorting technique, followed by artificial insemination.