Pregnancy Conception Calculator

Estimate your conception date based on your due date, last period, or ultrasound.

Finding the Date of Conception

While many parents find it exciting to know exactly when their baby was conceived, it can be difficult to pinpoint the precise day. Our calculator uses several common methods to provide an estimated conception window, helping you understand the timeline of your pregnancy journey.

How Conception Happens

Conception occurs when a sperm fertilizes an egg. This usually happens in the fallopian tube about 12 to 24 hours after ovulation. However, because sperm can live for up to five days, intercourse several days before ovulation can still lead to pregnancy.

Accuracy of Dates

Most methods for estimating conception date are based on averages. Unless you were tracking your ovulation precisely or having infrequent intercourse, the estimated date should be considered a likely window rather than a certainty.