1. What is the Due Date by Ovulation Calculation?

The due date calculation based on ovulation day is one of the most accurate methods for determining pregnancy due date. It adds 266 days (38 weeks) to the known ovulation date, representing the typical gestation period from conception.

2. How Does the Calculator Work?

The calculator uses the simple formula:

Where:

• Ovulation Day — The known date of ovulation/conception
• 266 days — Standard length of human gestation from conception

Explanation: This method is more accurate than last menstrual period (LMP) calculations as it doesn't rely on estimating ovulation timing.

3. Importance of Accurate Due Date Calculation

Details: Knowing the accurate due date helps in proper prenatal care scheduling, monitoring fetal development, and planning for delivery. It's especially important for high-risk pregnancies.

4. Using the Calculator

Tips: Enter the exact date of ovulation (if known from tracking) or conception date. The calculator will add 266 days (38 weeks) to determine the due date.

5. Frequently Asked Questions (FAQ)

Q1: How accurate is this method?
A: When ovulation date is known precisely, this is the most accurate due date calculation method, with only ±5 days variation.

Q2: Why 266 days instead of 280 days?
A: 280 days (40 weeks) is from LMP, assuming ovulation on day 14. 266 days is from actual conception.

Q3: What if I only know conception date?
A: Use conception date as ovulation typically occurs within 24 hours before conception.

Q4: Does this account for early delivery?
A: No, this calculates the expected due date. About 5% of women deliver on their due date.

Q5: Should I adjust for IVF pregnancies?
A: For IVF, use embryo transfer date + 266 days (or adjust for embryo age at transfer).