1. What is Naegele's Rule?

Naegele's Rule is a standard way of calculating the due date for a pregnancy by adding 280 days (40 weeks) to the first day of the woman's last menstrual period (LMP). This method assumes a regular 28-day menstrual cycle.

2. How Does the Calculator Work?

The calculator uses Naegele's Rule:

Where:

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

Explanation: The calculation starts from the first day of your last period, not the date of conception.

3. Importance of Due Date Calculation

Details: An accurate due date helps monitor fetal development, schedule prenatal tests, and prepare for delivery. Only about 5% of women deliver on their exact due date.

4. Using the Calculator

Tips: Enter the first day of your last menstrual period. For best results, use the date from your last normal period before you got pregnant.

5. Frequently Asked Questions (FAQ)

Q1: What if my cycle isn't 28 days?
A: The calculator assumes a 28-day cycle. If your cycle is longer or shorter, your healthcare provider may adjust the due date.

Q2: How accurate is this calculation?
A: It provides a good estimate, but ultrasound measurements in early pregnancy are more accurate for dating.

Q3: What is the normal range for delivery?
A: Most women deliver between 37-42 weeks. Babies born before 37 weeks are considered premature.

Q4: Can I calculate conception date from this?
A: Conception typically occurs about 14 days after LMP in a 28-day cycle, but this varies.

Q5: What if I don't remember my LMP?
A: An early ultrasound (first trimester) can provide the most accurate due date estimation.