Pregnancy Due Date Calculator
Find out when you'll meet your little one based on your last period.
How is my due date calculated?
Your estimated due date is calculated using Naegele's Rule, which adds 280 days (40 weeks) to the first day of your last menstrual period (LMP). This assumes a standard 28-day cycle.
Most pregnancies last between 37 and 42 weeks. Only about 4% of babies are born on their exact due date, so consider this an estimate rather than a deadline!
Understanding Trimesters
- First Trimester: Weeks 1-12. The baby's body structure and organ systems develop.
- Second Trimester: Weeks 13-27. The "golden period" where many women feel more energetic.
- Third Trimester: Weeks 28-40+. The final stretch as your baby grows and prepares for birth.