Pregnancy Conception Calculator
Estimate your conception date based on your due date, last period, or ultrasound information. This calculator also provides a possible range of days during which conception might have occurred.
Calculate Conception Date
Choose your calculation method and enter the required information
Related Calculators
When Did I Conceive?
Many women ask this question when trying to figure out the exact day their pregnancy began. Often, gestational age is calculated from the first day of the mother's last menstrual period, but biologically, conception occurs during ovulation and fertilization.
Because there are many factors surrounding conception, it's difficult to pinpoint an exact date. This calculator helps estimate the date range of conception and possible days during which sexual intercourse might have led to conception.
Calculation Methods
Last Menstrual Period
Conception usually occurs around 11-21 days after the first day of the last period for women with regular cycles. This method is based on typical ovulation timing but can be less accurate for women with irregular periods.
Due Date
An estimated due date from a healthcare provider, usually based on ultrasound, can be used to calculate backwards to determine possible conception dates.
Ultrasound
Ultrasound measurements can provide accurate gestational age, especially in early pregnancy. This method is often more accurate than calculations based on last menstrual period alone.
Fertilization, Conception, and Pregnancy
Fertilization occurs when sperm and egg combine in the fallopian tube, creating a fertilized egg and beginning embryo development. Conception, medically and scientifically, requires both fertilization and implantation into the uterine wall.
A woman is considered pregnant when the fertilized egg has implanted into the wall of her uterus. This medical definition aligns with established scientific understanding and federal policy regarding pregnancy.