Pregnancy Due Date Calculator
Estimate your due date from the last menstrual period (LMP).
Enter the date of your last menstrual period to estimate the due date (LMP + 280 days) and see current week, trimester and days remaining. Always confirm with a clinician.
Common use cases
- Estimate the due date early in pregnancy
- Track week-by-week progress and trimester transitions
- Plan parental leave around the expected delivery date
- Count down days remaining until the due date
Frequently asked questions
How accurate is the LMP method?▾
Roughly ±2 weeks for most pregnancies. First-trimester ultrasound is more accurate and is used to refine the date.
What's Naegele's rule?▾
LMP + 280 days (or LMP + 9 months + 7 days). Assumes a 28-day cycle with ovulation on day 14.
Should I rely on this?▾
No — this is an estimate only. Use it as a starting point and confirm with prenatal care.