Navigate Up

Pregnancy Center - A-Z Index


Print This Page

Ovulation Calculator

Ovulation Calculator

Some women have no idea when they've ovulated, while others can tell the exact moment it happened. In a typical menstrual cycle, an egg grows within a follicle in the ovary for two weeks, starting on the first day of your menses. Then, a hormone called lutenizing hormone (LH) rises dramatically and triggers the egg to be released from the ovary. The release of the egg is called ovulation.

When you ovulate, one of your eggs is carried into the fallopian tube. If a man's sperm makes its way to the same spot within the next 6 to 12 hours, it may fertilize that egg. You're not actually pregnant until the fertilized egg, called a zygote, travels the rest of the way down the fallopian tube and attaches itself to the wall of your uterus or, in unfortunate cases, attaches elsewhere and causes an ectopic pregnancy.

The catch: The average egg lives for fewer than 24 hours, and the average sperm lives for less than 72 hours, so they have to get acquainted during the first few hours after sex if you're going to conceive. The moral of the story: If your goal is to get pregnant, you should aim to make love at least every other day during the middle of your cycle. Studies have shown that sex must occur before ovulation in order to become pregnant. Kits that detect LH and measure your basal body temperature can help predict the exact time that you will be ovulating. Ideally, you should have intercourse on the day before, of, and after the LH kit turns positive.

Use the following tool as a quick way to get an idea of when you ovulate. Please note that ovulation is tricky to pinpoint; see our timing and fertility article for more information.

Calculator-1: Ovulation Calculator

Number of Days in Cycle Ovulation Day
(Counting from First Day of Cycle)

NOTE: Many factors can affect the accuracy of this tool, including irregular menstrual cycles. This calculator should not be used as a method of preventing pregnancy.

Updated: 12/9/2012

Irina Burd, MD, PhD, Maternal Fetal Medicine, Johns Hopkins University, Baltimore, MD. Review provided by VeriMed Healthcare Network.

©  UPMC | Affiliated with the University of Pittsburgh Schools of the Health Sciences
Supplemental content provided by A.D.A.M. Health Solutions. All rights reserved.

For help in finding a doctor or health service that suits your needs, call the UPMC Referral Service at 412-647-UPMC (8762) or 1-800-533-UPMC (8762). Select option 1.

UPMC is an equal opportunity employer. UPMC policy prohibits discrimination or harassment on the basis of race, color, religion, ancestry, national origin, age, sex, genetics, sexual orientation, gender identity, marital status, familial status, disability, veteran status, or any other legally protected group status. Further, UPMC will continue to support and promote equal employment opportunity, human dignity, and racial, ethnic, and cultural diversity. This policy applies to admissions, employment, and access to and treatment in UPMC programs and activities. This commitment is made by UPMC in accordance with federal, state, and/or local laws and regulations.

Medical information made available on is not intended to be used as a substitute for professional medical advice, diagnosis, or treatment. You should not rely entirely on this information for your health care needs. Ask your own doctor or health care provider any specific medical questions that you have. Further, is not a tool to be used in the case of an emergency. If an emergency arises, you should seek appropriate emergency medical services.

For UPMC Mercy Patients: As a Catholic hospital, UPMC Mercy abides by the Ethical and Religious Directives for Catholic Health Care Services, as determined by the United States Conference of Catholic Bishops. As such, UPMC Mercy neither endorses nor provides medical practices and/or procedures that contradict the moral teachings of the Roman Catholic Church.

Pittsburgh, PA, USA