📅 Pregnancy Tool
Due Date Calculator
Calculate your estimated due date (EDD) and see exactly how far along you are in your pregnancy based on your last period, conception date, or IVF transfer.
Pregnancy Due Date Calculator
Estimated Due Date
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How Far Along
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Conception Date
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Trimester
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How is the Due Date Calculated?
A full-term pregnancy is estimated to last 280 days (40 weeks) from the first day of the last menstrual period (LMP), or 266 days (38 weeks) from conception.
Naegele's Rule (Standard LMP method):
LMP Date + 7 Days - 3 Months + 1 Year
*Adjusted for cycle lengths other than 28 days.
Conception Method:
Conception Date + 266 Days
IVF Methods:
3-Day Transfer: Transfer Date + 263 Days
5-Day Transfer: Transfer Date + 261 Days
LMP Date + 7 Days - 3 Months + 1 Year
*Adjusted for cycle lengths other than 28 days.
Conception Method:
Conception Date + 266 Days
IVF Methods:
3-Day Transfer: Transfer Date + 263 Days
5-Day Transfer: Transfer Date + 261 Days
Note: Only about 4% to 5% of babies are born on their exact estimated due date. Most babies arrive between 37 and 42 weeks.
Frequently Asked Questions
Can my due date change?
Yes. Your doctor or midwife may adjust your due date based on early ultrasound measurements, which are generally more accurate than menstrual dates, especially if your cycles are irregular.
Why is pregnancy counted from before conception?
Medical professionals date pregnancy from the Last Menstrual Period (LMP) because it's a known date for most women, whereas the exact day of ovulation/conception is often unknown. Therefore, you are considered "two weeks pregnant" at the time of conception.
What is considered a full-term pregnancy?
A pregnancy is considered "early term" from 37 weeks, "full term" from 39 weeks to 40 weeks and 6 days, "late term" in week 41, and "postterm" at 42 weeks and beyond.