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Due Date Calculation:
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The Conception Date Due Date Calculator estimates the expected delivery date based on the known date of conception. This calculation assumes a standard 266-day (38-week) gestation period from conception to birth.
The calculator uses the following simple formula:
Explanation: Human pregnancy typically lasts 266 days (38 weeks) from conception. This is different from the common "40 weeks" measurement which counts from the first day of the last menstrual period (LMP).
Details: Knowing the estimated due date helps healthcare providers monitor fetal development, schedule important prenatal tests, and prepare for delivery. It also helps expectant parents plan for the arrival of their baby.
Tips: Enter the known or estimated conception date. The calculator will add 266 days to this date to estimate the due date. For best accuracy, use conception date confirmed by ultrasound or fertility treatment records.
Q1: Why 266 days instead of 280 days (40 weeks)?
A: 280 days counts from the first day of the last menstrual period (LMP), while 266 days counts from conception (typically occurring about 14 days after LMP in regular cycles).
Q2: How accurate is this calculation?
A: While 266 days is the average, normal pregnancies can vary by ±2 weeks. Only about 5% of women deliver on their exact due date.
Q3: What if I don't know my conception date?
A: If you know your last menstrual period, use an LMP-based calculator instead. Conception typically occurs about 11-21 days after LMP.
Q4: Does this work for IVF pregnancies?
A: Yes, IVF pregnancies have precisely known conception dates, making this calculation particularly accurate.
Q5: Why might my doctor give a different due date?
A: Doctors may adjust based on early ultrasound measurements which can be more accurate than dates, especially if there's discrepancy with menstrual dates.