Pregnancy Due Date Calculator
Estimate your due date and current week of pregnancy.
Pregnancy Due Date Calculator
Your Result
How Due Date Is Estimated
The most common method (Naegele's rule) estimates a due date as 280 days (40 weeks) from the first day of your last menstrual period, assuming a typical 28-day cycle. If you know your conception date instead, the due date is estimated as 266 days (38 weeks) from that date.
This is an estimate, not a guarantee, only about 1 in 20 babies are born on their exact due date. Your healthcare provider may adjust this estimate based on ultrasound measurements.
Frequently Asked Questions
How accurate is this due date estimate?
It's a widely used standard estimate, but actual delivery dates vary naturally by up to two weeks in either direction. Ultrasound dating from your provider is generally more precise.
What if my cycle isn't a typical 28 days?
This calculator assumes a standard 28-day cycle. If yours is significantly different, your healthcare provider can adjust the estimate accordingly.
What are the three trimesters?
The first trimester covers weeks 1-13, the second covers weeks 14-27, and the third covers weeks 28 through delivery, roughly week 40.