Calculate Baby Delivery Date

Pregnancy due dates are estimated based on the first day of your last menstrual period (LMP) or the date of a positive pregnancy test. This calculator helps you determine your estimated delivery date and track your pregnancy timeline.

How to Use This Calculator

To calculate your estimated baby delivery date:

Enter the first day of your last menstrual period (LMP) or the date of your positive pregnancy test.
Select whether you want to calculate based on LMP or the date of a positive test.
Click "Calculate" to see your estimated due date.

The calculator uses standard pregnancy duration of 40 weeks (280 days) from the first day of your last menstrual period.

How Pregnancy Due Dates Are Calculated

Pregnancy due dates are typically calculated based on the first day of your last menstrual period (LMP). The standard pregnancy duration is 40 weeks (280 days) from the first day of your last menstrual period.

Due Date = Last Menstrual Period + 280 days

For example, if your last menstrual period started on January 1, your estimated due date would be October 31 (280 days later).

Some healthcare providers may use ultrasound results to calculate a more precise due date, but the calculator provides a general estimate based on standard pregnancy duration.

Example Calculation

Let's say your last menstrual period started on March 15, 2023. Using the standard 40-week pregnancy duration:

Due Date = March 15, 2023 + 280 days Due Date = December 12, 2023

Your estimated baby delivery date would be December 12, 2023.

Note: This is an estimate. Actual delivery dates can vary by several days or weeks.

Frequently Asked Questions

How accurate is the estimated due date?: The estimated due date is based on standard pregnancy duration and may vary by several days or weeks. Ultrasound results provide a more precise due date.
Can I use the date of a positive pregnancy test instead of my last menstrual period?: Yes, you can use the date of a positive pregnancy test. The calculator will add 280 days to this date to estimate your due date.
What if I don't remember my last menstrual period?: If you don't remember your last menstrual period, you can use the date of a positive pregnancy test or consult with your healthcare provider for a more accurate estimate.
How do I track my pregnancy timeline?: You can use this calculator to track your pregnancy timeline by entering different dates to see how many weeks you are pregnant.