Baby Expected Date Calculator

Pregnancy is a special time, and knowing your baby's expected due date can help you prepare for the arrival. Our baby expected date calculator makes it easy to estimate your due date based on your last menstrual period or ultrasound date.

How to Use This Calculator

To calculate your baby's expected due date, you'll need either your last menstrual period (LMP) date or your ultrasound date. Here's how to use the calculator:

Select whether you want to use your last menstrual period date or ultrasound date.
Enter the relevant date in the provided field.
If you're using an ultrasound date, enter the number of weeks your baby was at the time of the scan.
Click the "Calculate" button to see your estimated due date.

The calculator will display your estimated due date, along with additional information about your pregnancy timeline.

Formula Used

The standard pregnancy duration is 40 weeks (280 days) from the first day of the last menstrual period. The due date is calculated by adding 280 days to the last menstrual period date.

Formula

Due Date = Last Menstrual Period Date + 280 days

For ultrasound dates, the formula adjusts based on the baby's age at the scan:

Due Date = Ultrasound Date + (40 weeks - weeks at scan) × 7 days

This formula provides a general estimate. Individual pregnancies may vary, and medical professionals recommend using this as a guideline rather than an exact prediction.

Worked Example

Let's say your last menstrual period started on January 1, 2023. Using the calculator:

Select "Last Menstrual Period Date"
Enter "2023-01-01"
Click "Calculate"

The calculator will show that your estimated due date is October 29, 2023.

Note

This is an estimate. Your actual due date may vary by several days. Always consult with your healthcare provider for the most accurate information.

Frequently Asked Questions

How accurate is the baby expected date calculator?

The calculator provides a general estimate based on standard pregnancy duration. Individual pregnancies may vary, and medical professionals recommend using this as a guideline rather than an exact prediction.

Can I use an ultrasound date instead of my last menstrual period?

Yes, you can use either your last menstrual period date or an ultrasound date. If you use an ultrasound date, you'll need to enter the number of weeks your baby was at the time of the scan.

What if my due date changes during pregnancy?

Due dates can change during pregnancy. If you have an ultrasound after the initial calculation, you should use the more recent date for a more accurate estimate.