Pregnancy Due Date Calculator
Estimate your pregnancy due date and current week of gestation from your last menstrual period.
Pregnancy Due Date Calculator
Estimate your pregnancy due date and current week of gestation from your last menstrual period.
Enter the date in YYYY-MM-DD format
Real-World Examples
LMP = 2024-01-01 → 2024-01-01 + 280 days
Due date: October 7, 2024
LMP = 2024-03-15, today = 2024-04-15
4 weeks 4 days pregnant
LMP = 2024-01-10, today = 2024-06-10
21 weeks 3 days, second trimester
Common Mistakes to Avoid
Using conception date instead of LMP
Fix: Naegele's rule adds 280 days to the first day of the last menstrual period, not the conception date. Ovulation typically occurs ~14 days after LMP, so using conception date would shift the estimate two weeks early.
Assuming the due date is exact
Fix: Only ~5% of babies are born on their due date. The estimate is a midpoint of a normal range (37–42 weeks). Births before 37 weeks are preterm; after 42 weeks are post-term and may require induction.
Ignoring cycle length
Fix: The 280-day rule assumes a 28-day cycle. For a 35-day cycle, ovulation is later, so add about 7 days to the estimate. An ultrasound in the first trimester gives a more accurate date.