Result
Estimated due date
Wed, 06 Jan 2027
245 days from today
- Current pregnancy week4 weeks 6 days
- TrimesterFirst trimesterNote
- Days since start event34
- Estimated conception dateWed, 15 Apr 2026
- Method usedNaegele's rule (LMP + 280 d)
How to use this calculator
- LMP is the most common method — pick the first day of your last period.
- IVF transfer dates: be sure whether your transfer was 3-day or 5-day embryo (your clinic told you).
- Conception dates are only reliable if you have ovulation tracking (BBT or LH strips).
- Always confirm with your doctor — first-trimester ultrasound dating is more accurate.
About this tool
A pregnancy lasts about 40 weeks counted from the first day of the last menstrual period — a calculation called Naegele's rule, used since the 19th century. If you know the conception date instead (often the case after IVF or with carefully tracked cycles), the math shifts by 14 days. Only about 5 % of babies arrive on the exact predicted day; "term" is anywhere from 37 to 42 weeks. The due date is mainly a planning anchor for prenatal appointments, not a deadline. An ultrasound between weeks 8 and 14 gives a more accurate date than LMP alone.
Frequently asked
About ±2 weeks for the actual delivery — only 5 % of babies are born on the exact date. First-trimester ultrasound dating is the gold standard; LMP-based dates can be off by up to 2 weeks if cycles are irregular.
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