When Is The Baby Due Calculator

Pregnancy due dates are calculated based on the first day of your last menstrual period (LMP) or the date of your ultrasound. This calculator helps you determine when your baby is expected to be born.

How to Use This Calculator

Using our due date calculator is simple:

Enter the date of your last menstrual period (LMP) or the date of your ultrasound.
If you know your estimated due date (EDD) from a previous calculation, you can enter that instead.
Click "Calculate" to see your estimated due date.

The calculator will display your estimated due date, the date of conception, and the number of weeks and days until your due date.

How the Due Date Calculation Works

The standard method for calculating a pregnancy due date is to add 280 days (40 weeks) to the first day of your last menstrual period (LMP). This is based on the average length of a pregnancy.

Formula

Due Date = Last Menstrual Period (LMP) + 280 days

Weeks Pregnant = (Current Date - LMP) / 7

For example, if your LMP was January 1, 2023, your due date would be October 31, 2023 (280 days later).

Note: This is an estimate. Actual due dates can vary by several days due to individual differences in pregnancy length.

Examples of Due Date Calculations

Here are a few examples of how the due date calculator works:

Example 1: Last Menstrual Period (LMP)

If your last menstrual period started on May 15, 2023, your estimated due date would be:

May 15, 2023 + 280 days = February 12, 2024
This means you would be due on February 12, 2024.

Example 2: Ultrasound Date

If you had an ultrasound on June 1, 2023, and it showed your baby was 12 weeks old, your estimated due date would be:

June 1, 2023 + (40 weeks - 12 weeks) = June 1, 2023 + 28 weeks = February 12, 2024
This means you would be due on February 12, 2024.

Example 3: Current Pregnancy Week

If today is July 15, 2023, and your LMP was May 15, 2023, your pregnancy week would be:

(July 15, 2023 - May 15, 2023) / 7 days = 61 days / 7 ≈ 8.7 weeks
This means you are approximately 8 weeks and 5 days pregnant.

Frequently Asked Questions

How accurate is the due date calculator?: The due date calculator provides an estimate based on the average length of pregnancy. Actual due dates can vary by several days due to individual differences in pregnancy length.
Can I use this calculator if I had an ultrasound?: Yes, you can enter the date of your ultrasound and the number of weeks your baby was to determine your estimated due date.
What if I don't know my last menstrual period?: If you don't know your LMP, you can use the date of your ultrasound or estimated due date from a previous calculation.
How do I know if my pregnancy is on track?: Regular prenatal checkups with your healthcare provider can help determine if your pregnancy is progressing as expected.
What should I do if my due date changes?: If your due date changes significantly, consult with your healthcare provider to discuss any potential concerns.