Pregnancy Due Date Calculator (EDD)
Calculate your estimated due date from last period, conception date, or IVF transfer date.
Calculation Method
Last Menstrual Period (LMP)
Conception Date
IVF Transfer (Day 5 Blastocyst)
First day of your last period
Estimated Due Date (EDD)
Saturday, 31 October 2026
Term Window
Early Term (38 weeks)
Baby is early-term — ideal to wait if possible
Saturday, 17 October 2026
✅ Full Term (40 weeks)
Your estimated due date
Saturday, 31 October 2026
Late Term (41 weeks)
Induction often discussed after 41 weeks
Saturday, 7 November 2026
LMP (reference date)
Pregnancy start reference
Saturday, 24 January 2026
⚕️ Medical note: Only 5% of babies are born exactly on their due date. A birth is considered full-term between 39–40 weeks 6 days. Your doctor may confirm or adjust the EDD after the first trimester ultrasound scan.
About Due Date Calculator
Naegele's Rule (LMP method)
The most common method: add 280 days (40 weeks) to the first day of your LMP. This assumes a regular 28-day cycle with ovulation on Day 14. It was developed by German obstetrician Franz Naegele in 1812 and remains the clinical standard worldwide.
3 methods explained
LMP method: Add 280 days to first day of last period
Conception method: Add 266 days (38 weeks) from known conception date
IVF Day 5 blastocyst: Add 261 days from Day 5 transfer date
All three calculate the same EDD — just from different reference points
First trimester ultrasound
A dating scan at 10–13 weeks gives the most accurate EDD
If the scan date differs from LMP date by more than 5–7 days, the scan date takes precedence
Crown-rump length (CRL) measurement is used to estimate gestational age
Book your first appointment by Week 8 to get an early ultrasound scan
🔒 All calculations happen in your browser — no data is sent to any server. Results are for informational purposes only.