How to Calculate a Due Date Using How Many Weeks Along

Generally your obstetrician or midwife will inform you of your due date but you can also attempt to figure out your due date on your own. Unless you have been scheduled for a cesarean procedure, there is no way to calculate the exact date and time that your baby will arrive but knowing your estimated due date will give you an idea about when to expect your baby. You can use your estimated weeks along to calculate your approximate due date by following a few simple calculations.

Using Estimated Weeks Along

• 1

  Write down the number 38 on a piece of paper. This number represents the typical length of a pregnancy in weeks from the time of conception. Write down the number of weeks you are along either right next to or under the number 38.

• 2

  Subtract the number of weeks you are along from the number 38. The sum of these two numbers will be the amount of weeks you have left.

• 3

  Count the number of weeks you have left in your pregnancy on a calendar. This date is your estimated due date.

Using Estimated Menstrual Cycle Date

• 1

  Write down the first day of your last menstrual cycle on a sheet of paper.

• 2

  Add seven days to the first day of your period.

• 3

  Subtract three months from your answer. Apply your answer to your appropriate year (either the current or next year, depending on date of conception). The resulting date will be your approximate due date.