How to Calculate a Birth Date Delivery

Pregnancy is a fun, exciting, and exhausting experience. Learning when your due date is can be important in preparing for the arrival of your newborn. Doctors determine the due date using a math equation based on the first day of your last menstrual cycle. You don't have to be a math whiz to figure out your estimated due date. While the equation does not guarantee to pinpoint the exact birth date, it will give your a general idea of when your baby is to be born.

Instructions

Calculating on Your Own

• 1

  Add seven days to the first day of your last period.

• 2

  Subtract three months from the date you have from step 1. So if the date from step 1 is May 1, you would use February 1 as your starting point.

• 3

  Add one year to the date you calculate in step 2. This is your estimated due date.

Using an Online Calculator

• 4

  Choose an online due date calculator. (See Resources for examples of two.)

• 5

  Enter the first day of your last period using the drop down menu. Some calculators allow you to enter the date of conception instead, if known.

• 6

  Click "Calculate my due date." Your estimated due date and other pregnancy tips will be displayed.