Due Date Calculator
Calculate your due date from conception date, IVF transfer, or last menstrual period. Includes trimester milestones and antenatal appointment schedule.
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Due Date
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How Due Dates Are Calculated
The estimated due date (EDD) depends on your starting point. Conception date adds 266 days (38 weeks of development). LMP adds 280 days (40 weeks, accounting for the 2-week gap before ovulation). IVF transfers use a shorter window because the embryo's age is precisely known.
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Due Date Calculation Methods
| Method | Days Added | Notes |
|---|---|---|
| Conception Date | +266 days | Most direct method |
| LMP (Last Period) | +280 days | Standard medical method |
| IVF Day-5 Transfer | +263 days | Blastocyst stage |
| IVF Day-3 Transfer | +265 days | Cleavage stage |
| Early Ultrasound | Calculated from CRL | Most accurate |
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Frequently Asked Questions
Only about 5% of babies arrive on their exact due date. Most are born within 2 weeks either side. Early ultrasound dating (before 12 weeks) is the most accurate method, correcting for variations in cycle length and ovulation timing.
Full term is 39–40 weeks. Early term is 37–38 weeks, late term is 41 weeks, and post-term is 42+ weeks. Doctors typically consider induction after 41–42 weeks if labour has not started.