1. What is the Due Date Calculation?

The due date calculation estimates the expected date of delivery (EDD) based on the first day of the last menstrual period (LMP). This is commonly known as Naegele's rule.

2. How Does the Calculator Work?

The calculator uses the standard 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 the last menstrual period, which is the standard duration of pregnancy.

3. Importance of Due Date Calculation

Details: Accurate due date estimation is crucial for prenatal care, monitoring fetal development, and planning for delivery. It helps healthcare providers schedule important tests and assessments at appropriate times during pregnancy.

4. Using the Calculator

Tips: Enter the first day of your last menstrual period in the format YYYY-MM-DD. The calculator will add 280 days to this date to estimate your due date.

5. Frequently Asked Questions (FAQ)

Q1: Is this calculation accurate for all pregnancies?
A: While it provides a good estimate, 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: If LMP is unknown, an ultrasound measurement in early pregnancy can provide a reliable estimate of gestational age.

Q3: Does this work for irregular cycles?
A: The calculation assumes a 28-day cycle. Women with irregular cycles may need adjustment based on cycle length or early ultrasound.

Q4: Why 280 days?
A: This represents 40 weeks of gestation, counting from the LMP (which is about 2 weeks before conception typically occurs).

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 the LMP-based calculation.