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Due Date Calculation Formula:
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The Due Date Calculator Based On Conception Date estimates the expected delivery date by adding 266 days (38 weeks) to the known conception date. This method provides an accurate prediction when the exact conception date is known.
The calculator uses the standard pregnancy duration formula:
Where:
Explanation: This calculation assumes a standard 38-week pregnancy duration from conception to delivery, which corresponds to 40 weeks from the first day of the last menstrual period (LMP).
Details: Accurate due date calculation is essential for proper prenatal care, monitoring fetal development, planning for delivery, and ensuring optimal timing for medical interventions and preparations.
Tips: Enter the exact conception date in the date picker. The calculator will automatically compute and display the estimated due date. Ensure the conception date is accurate for the most reliable result.
Q1: Why 266 days instead of 280 days?
A: 280 days is calculated from the first day of the last menstrual period (LMP), while 266 days is from the actual conception date, accounting for the typical 2-week difference.
Q2: How accurate is this calculation method?
A: When the exact conception date is known, this method is highly accurate. However, only about 5% of babies are born exactly on their due date.
Q3: What if I don't know my exact conception date?
A: If the conception date is unknown, use the LMP-based calculator which adds 280 days from the first day of your last menstrual period.
Q4: Can the due date change during pregnancy?
A: Yes, healthcare providers may adjust the due date based on ultrasound measurements, especially if there's a significant discrepancy from the initial calculation.
Q5: What is considered a full-term pregnancy?
A: A full-term pregnancy is between 37 weeks (259 days) and 42 weeks (294 days) from the first day of the LMP, or 35-40 weeks from conception.