EDD Calculation Formula:
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The Pregnancy Calculator Conception Date Known calculates the estimated due date (EDD) when the exact conception date is known. This provides a more accurate pregnancy timeline compared to calculations based on the last menstrual period.
The calculator uses the standard pregnancy calculation 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 essential for proper prenatal care, monitoring fetal development, planning for delivery, and ensuring the best outcomes for both mother and baby.
Tips: Enter the exact known conception date. The calculator will automatically compute the estimated due date by adding 266 days (38 weeks) to the conception date.
Q1: Why 266 days instead of 280 days?
A: 280 days is calculated from the last menstrual period (LMP), while 266 days is from actual conception. Conception typically occurs about 14 days after LMP.
Q2: How accurate is this calculation?
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 the exact conception date?
A: If the conception date is unknown, use the last menstrual period method (LMP + 280 days) for estimation.
Q4: Does this account for variations in gestation?
A: The 266-day period is an average. Actual gestation can vary from 259 to 287 days (37-41 weeks) and still be considered normal.
Q5: When should prenatal care begin?
A: Prenatal care should begin as soon as pregnancy is confirmed, typically within the first 8 weeks of gestation.