Fertility Calculators: Ovulation and Conception

Use these fertility calculators to estimate when ovulation may occur, identify your fertile window, and work back to a possible conception date. Calendar of Ovulation and Fertility and Fertile Days and Ovulation help people planning a pregnancy track likely fertile days. Date of Conception estimates when conception may have happened.Safe Days identifies days estimated to be outside the fertile window, but cycle-based predictions are not reliable birth control. These tools are useful for anyone tracking menstrual cycles or trying to conceive. Results are estimates because ovulation can vary from month to month.

Safe Days

Enter the first day of your last menstrual period, your cycle length, and your menstruation duration to see a calendar of estimated menstrual, fertile, and lower-fertility days. No day is guaranteed safe from pregnancy.

Fertile Days and Ovulation

Enter the first day of your last menstrual period and your average cycle length to estimate your ovulation date and the dates two days before and after it.

Implantation Date

Estimate when a fertilized egg is most likely to implant in the uterus. Enter your ovulation or conception date to get your implantation window of 6–12 days past ovulation.

Date of Conception

Estimate a conception date from the first day of your last menstrual period, your cycle length, and the length of the second part of your cycle. The displayed date may be one month later than the intended estimate.

Period

Estimate your next period date and upcoming cycles. Enter the first day of your last period, your average cycle length, period length, and how many cycles to show.

Pregnancy Test Date

Find out the best day to take a home pregnancy test. Enter your ovulation date (or expected period date) and your luteal phase length to get your earliest and most accurate testing dates.

Motile Sperm Count

Enter semen volume, sperm concentration, and total motility from your semen analysis report to get your total motile sperm count (TMSC) and what it means for natural conception, IUI, and IVF.