Free Tool
When is your baby due?
Enter your last period, conception date, or IVF transfer date and get your estimated due date in seconds.
I know my
This calculator provides an estimate. Your provider will confirm your due date, often after an early ultrasound.
How is my due date calculated?
Most due dates are estimated using Naegele's rule: add 280 days (40 weeks) to the first day of your last menstrual period. This assumes a 28-day cycle with ovulation on day 14.
If you know your conception date, we add 266 days (38 weeks). For IVF transfers, we calculate from your transfer date adjusted for embryo age (5-day or 3-day).
Your actual due date may shift after your first ultrasound. Only about 4% of babies arrive on their estimated date, but most are born within two weeks of it.
What happens each trimester?
First Trimester
Weeks 1 to 13. Your baby's organs form, and you may feel fatigue, nausea, and tenderness. This is a great time to find your prenatal provider.
Second Trimester
Weeks 14 to 27. Energy returns, you will feel movement, and the anatomy scan happens around week 20. Start thinking about your birth plan.
Third Trimester
Weeks 28 to 40+. Frequent appointments, nesting, and preparing your postpartum support. Make sure your team is assembled.