1. What is the Pregnancy Due Date Calculator?

The pregnancy due date calculator estimates the expected date of delivery (EDD) based on the first day of your last menstrual period (LMP). This calculation uses Naegele's rule which assumes a 280-day (40-week) pregnancy from the LMP.

2. How Does the Calculator Work?

The calculator uses the following formula:

Where:

• LMP — First day of last menstrual period
• 280 days — Standard length of pregnancy (40 weeks)

Explanation: The calculation adds 280 days (40 weeks) to the first day of your last menstrual period. This is based on the average length of human gestation.

3. Importance of Due Date Calculation

Details: Knowing your estimated due date helps healthcare providers monitor fetal growth and development, schedule important prenatal tests, and prepare for delivery.

4. Using the Calculator

Tips: Enter the first day of your last menstrual period in the format YYYY-MM-DD. The calculator will show your estimated due date and current gestational age.

5. Frequently Asked Questions (FAQ)

Q1: How accurate is this due date calculation?
A: Only about 5% of women deliver on their exact due date. Most deliver within 2 weeks before or after.

Q2: What if I don't know my LMP?
A: An early ultrasound can provide a more accurate due date estimation if you're unsure of your LMP.

Q3: Does this work for irregular cycles?
A: The calculation assumes a 28-day cycle. If your cycles are significantly longer or irregular, the due date may need adjustment.

Q4: What's the difference between gestational age and fetal age?
A: Gestational age counts from LMP (about 2 weeks before conception), while fetal age counts from conception.

Q5: Can the due date change?
A: Yes, healthcare providers may adjust your due date based on ultrasound measurements in early pregnancy.