1. Pregnancy Due Date Calculation

The due date is calculated by adding 266 days (38 weeks) to the conception date. This is based on the typical duration of human pregnancy from conception to birth. Most pregnancies last between 37 and 42 weeks.

2. How the Calculator Works

The calculator uses the standard formula:

Where:

• 266 days represents the average gestation period from conception
• This equals approximately 38 weeks

Note: Only about 5% of women deliver on their exact due date, but it serves as an important reference point for prenatal care.

3. Importance of Accurate Due Date

Details: An accurate due date helps healthcare providers monitor fetal development, schedule important tests, and determine if intervention is needed for post-term pregnancies.

4. Using the Calculator

Instructions: Enter the known or estimated conception date. The calculator will add 266 days to estimate the due date.

5. Frequently Asked Questions (FAQ)

Q1: How accurate is this calculation?
A: Very accurate if conception date is known precisely. However, only about 5% of women deliver on their exact due date.

Q2: What if I don't know my conception date?
A: If you know your last menstrual period (LMP), use our LMP-based calculator instead (add 280 days to LMP).

Q3: Why 266 days instead of 280?
A: 280 days (40 weeks) is counted from the last menstrual period, while 266 days (38 weeks) counts from conception (typically 2 weeks after LMP).

Q4: Can the due date change?
A: Early ultrasound measurements may adjust the due date if they differ significantly from the date calculated from conception.

Q5: What percentage of babies are born by the due date?
A: Only about 5% are born on the exact due date, but about 60% are born within one week, and 90% within two weeks.