Pregnancy Calculator
Gestational age counts from the first day of the last menstrual period; estimated due date is 280 days later.
This calculator is free to use. Enable JavaScript to enter your values and see a result instantly.
How it works
Gestational age counts from the first day of the last menstrual period; estimated due date is 280 days later.
Worked example
At 140 days after the last period, the estimate is 20 weeks.
Keep in mind
Ultrasound and clinical dating can change the estimated due date.