1. What is the Due Date Calculator?

The Due Date Calculator estimates when your baby is likely to be born based on your last menstrual period (LMP). This calculation uses Naegele's rule which adds 280 days (40 weeks) to the first day of your last menstrual period.

2. How Does the Calculator Work?

The calculator uses the standard pregnancy calculation:

Where:

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

Explanation: This calculation assumes a regular 28-day menstrual cycle with ovulation occurring on day 14.

3. Importance of Due Date Calculation

Details: Knowing your estimated due date helps healthcare providers monitor fetal development, schedule important tests, and determine if the pregnancy is progressing normally.

4. Using the Calculator

Tips: Enter the first day of your last menstrual period. For best accuracy, you should know your cycle length and ovulation date if possible.

5. Frequently Asked Questions (FAQ)

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

Q2: What if my cycle isn't 28 days?
A: The calculation can be adjusted for different cycle lengths by adding (cycle length - 28) days to the due date.

Q3: Can ultrasound change my due date?
A: Yes, early ultrasound measurements (especially first trimester) may adjust your due date if they differ significantly from LMP calculation.

Q4: What if I don't know my LMP?
A: If you don't know your LMP, an ultrasound can estimate your due date based on fetal measurements.

Q5: Why 280 days?
A: Pregnancy is typically counted as 40 weeks from LMP (about 38 weeks from conception), based on average human gestation.