Calculate your estimated due date (EDD) using LMP, conception date, ultrasound, or IVF transfer date. Includes full trimester breakdown and RANZCOG antenatal schedule.
| Trimester / Milestone | Date range |
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Only 4% of babies are born on their exact due date. Most births occur between 37–42 weeks (term pregnancy). A first-trimester ultrasound (crown-rump length measurement) is the most accurate method for dating a pregnancy, and takes precedence over LMP-based calculations.
EDD = LMP + 9 months + 7 days (for 28-day cycles). For cycles longer or shorter than 28 days, add or subtract the difference.
For IVF: Day-3 transfer EDD = transfer date + 263 days. Day-5 (blastocyst) EDD = transfer date + 261 days.