The pregnancy due date is an estimate of when the woman will deliver the baby. It can be calculated by using the formula below; taking the first day of your last menstrual period (LMP), adding 7 days, and then counting backward 3 months.
How Can I Figure out the Pregnancy Due Date?
LMP (first day of Last Menstrual Period) + 7 Days = Total 1
Total 1 – 3 Months = Due Date
For Example - If the first day of your LMP was August 20th:
August 20th + 7 Days = August 27
August 27th – 30 Days = May 27th
The due date is ONLY an estimated delivery date. Most women do not give birth on time, but typically within 1 week before or after the estimated due date. To learn more about the delivery see our labor and delivery section.