Pregnancy Due Date Calculator

Congratulations! Now that you’re pregnant, you’re probably wondering when your baby will make their appearance. Our due date calculator can help you figure out when to expect your new bundle of joy.

How Do You Use a Due Date Calculator?

A typical pregnancy lasts about 280 days — or 40 weeks — starting with the first day of your last normal menstrual period. There are three steps you need to follow to determine your estimated due date (EDD):

1. Determine the first day of your last menstrual period.
2. Count back three calendar months from the first day of your last menstrual period.
3. Add one year and seven days to that date.

Here’s an example: Say your last menstrual period began on September 9, 2024. Count back three calendar months to June 9, 2024. Add one year and seven days to arrive at your EDD of June 16, 2025.

How Accurate Are Due Date Predictions?

This three-step due date calculator, referred to as Naegele's Rule, is based on a normal 28-day menstrual cycle. Dates may have to be adjusted for longer or shorter menstrual cycles. However, even with adjustments, fewer than 10% of women actually give birth on their calculated due dates.

Delivery two weeks before or after the estimated due date is still considered normal.

In cases where the date of conception is known precisely, such as with in vitro fertilization, the EDD is calculated by adding 266 days to the date of conception.