What is the Pregnancy Due Date Calculator?
A due date calculator applies Naegele’s rule (due date ≈ first day of LMP + 280 days) or adds 266 days from an estimated conception date. We show approximate gestational age from LMP, current trimester, and days until due date.
Why people use this calculator
Quick planning and understanding of pregnancy timelines; ultrasound dating by a clinician remains the gold standard for individual care.
How to use the Pregnancy Due Date Calculator  summary
- Choose starting point: LMP (first day of last period) or known/estimated conception.
- Enter the date: Use the calendar picker (YYYY-MM-DD).
- Calculate: Review due date, trimester band and gestational weeks from today.
Tips for best results
Use these numbers as conversation starters with a qualified professional  not as a diagnosis. Track trends over weeks, not single days.