Ovulation Calculator

Fertility Calendar

What is Ovulation?

Ovulation is the process in which a mature egg is released from the ovary, pushed down the fallopian tube, and made available to be fertilized. The lining of the uterus has thickened to prepare for a fertilized egg. If conception does not occur, the uterine lining, as well as blood, will be shed during menstruation.

For women with regular menstrual cycles, ovulation typically occurs about 14 days before the start of the next period. However, this can vary from woman to woman and cycle to cycle. Understanding when you ovulate can help you plan for or prevent pregnancy.

What is the Fertile Window?

The fertile window is the period during which sexual intercourse can result in pregnancy. It includes the 5 days before ovulation and the day of ovulation itself. This is because sperm can live in the female reproductive tract for up to 5 days, while the egg is viable for fertilization for about 12-24 hours after ovulation.

The days with the highest probability of conception are the two days before ovulation and the day of ovulation. Having regular intercourse during your fertile window significantly increases your chances of getting pregnant.

How to Use This Calculator

1. Enter the first day of your last menstrual period (LMP)
2. Enter your average cycle length (the number of days from the start of one period to the start of the next)
3. For more accurate results, you can optionally specify your luteal phase length (the number of days between ovulation and your next period) in the Advanced Options

Signs and Symptoms of Ovulation

• Change in cervical mucus - becomes clear, stretchy, and resembles egg white
• Change in basal body temperature - slight increase (0.5-1°F) after ovulation
• Increased sex drive
• Breast tenderness
• Mild pelvic or abdominal pain (mittelschmerz)
• Light spotting
• Abdominal bloating
• Heightened sense of smell, taste, or vision

Important Notes

• This calculator provides estimates based on average cycle patterns and may not be accurate for everyone
• Women with irregular cycles may have difficulty predicting ovulation using this method
• Stress, illness, travel, and other factors can affect your cycle and ovulation timing
• For the most accurate ovulation prediction, consider using ovulation predictor kits (OPKs) or tracking basal body temperature
• If you have been trying to conceive for 12 months (or 6 months if over 35) without success, consult a healthcare provider
• This calculator should not be used as a form of birth control
• Fertility decreases with age, particularly after age 35 for women

Tips for Improving Fertility

• Maintain a healthy weight - both underweight and overweight can affect ovulation
• Eat a balanced diet rich in antioxidants, vitamins, and minerals
• Reduce stress through meditation, yoga, or other relaxation techniques
• Limit caffeine and alcohol consumption
• Quit smoking and avoid secondhand smoke
• Exercise regularly but avoid excessive intense workouts
• Get adequate sleep (7-9 hours per night)
• Take prenatal vitamins with folic acid
• Track your cycles to identify patterns
• Have regular intercourse throughout your cycle, especially during the fertile window