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Due Date Calculation Formula:
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The Due Date Calculator estimates the expected delivery date (EDD) when the conception date is known. It calculates the due date by adding 266 days to the known conception date, representing the typical human gestation period.
The calculator uses the simple formula:
Where:
Explanation: This calculation assumes a standard 266-day gestation period from conception to delivery, which corresponds to 38 weeks of pregnancy.
Details: Accurate due date calculation is crucial for prenatal care planning, monitoring fetal development, preparing for delivery, and scheduling important medical appointments and tests throughout pregnancy.
Tips: Enter the known 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. Conception typically occurs about 14 days after LMP.
Q2: How accurate is this calculation?
A: When the conception date is precisely known, this method is very accurate. However, only about 5% of babies are born exactly on their due date.
Q3: What if I don't know the exact conception date?
A: If the conception date is unknown, use the last menstrual period (LMP) method by adding 280 days to the first day of your last 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 factors can affect the actual delivery date?
A: Many factors including maternal health, fetal development, genetics, and whether it's a first pregnancy can influence when labor naturally begins.