What is an estimated due date during pregnancy?

Your due date (also known as your estimated due date) is a calculation of when you’re expected to give birth. Your EDD is important for you to know as you prepare to welcome your baby.

But remember, it’s only an estimated due date, not a deadline for your baby to arrive. Just 4 percent of babies are born on their EDD.

Our pregnancy Due Date Calculator (or estimated Due Date Calculator) can help. Here’s how to calculate your due date Opens a new window using your last period, conception date, IVF transfer date, or timing of your last ultrasound.

First day of the last period

Most pregnancies last around 40 weeks (or 38 weeks from conception), so typically the best way to estimate your due date is to count 40 weeks, or 280 days, from the first day of your last menstrual period (LMP). You can also subtract three months from the first day of your last period and add seven days. Or choose “last period” from the choices in our Due Date Calculator menu, above.

The first day of your LMP is how most healthcare providers estimate a baby’s due date.

Conception date

If you’ve been tracking ovulation symptoms Opens a new window or have been using ovulation test strips Opens a new window, you may be able to use your conception date to see how far along you are and when the baby is likely to arrive.

Just add 266 days to get your estimated due date. Or select “conception date” and let our pregnancy Due Date Calculator do the math for you.

Wondering when your baby was conceived? Use the Conception Date Calculator below to find out the most likely date.

Calculation Method