1. What is the Estimated Due Date?

The estimated due date (EDD) is the approximate date when a pregnant woman is expected to deliver. It's calculated as 280 days (40 weeks) from the first day of the last menstrual period (LMP), following Naegele's rule.

2. How Does the Calculator Work?

The calculator uses the standard pregnancy calculation:

Where:

• LMP — First day of last menstrual period
• 280 days — Equivalent to 40 weeks gestation

Explanation: This calculation assumes a regular 28-day menstrual cycle with ovulation occurring on day 14. The calculator also shows current gestational age based on today's date.

3. Importance of Due Date Calculation

Details: Accurate due date estimation is crucial for proper prenatal care scheduling, monitoring fetal growth, and determining if pregnancy continues beyond term (42 weeks).

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 the estimated date.

Q2: What if my cycles aren't regular?
A: For irregular cycles, an early ultrasound provides more accurate dating than LMP-based calculation.

Q3: Why 280 days if pregnancy is 9 months?
A: Pregnancy is actually about 9.5 lunar months (40 weeks). Months vary in length while weeks are consistent.

Q4: When should I see my doctor after calculating my due date?
A: Schedule your first prenatal visit as soon as you have a positive pregnancy test, typically around 8 weeks gestation.

Q5: Can the due date change?
A: Yes, healthcare providers may adjust the due date based on early ultrasound measurements if they differ significantly from LMP-based calculation.