Calculate due date, current week, trimester, and pregnancy milestones
Select a method and enter a date
Pregnancy Calculator is a free online tool that estimates your due date, current pregnancy week, trimester, and key milestones. Enter the first day of your last menstrual period (LMP) or your conception date, and the calculator uses Naegele's rule (LMP + 280 days) to determine your estimated due date. Track your progress with a visual progress bar, see your current week and day, know which trimester you are in, and view upcoming milestones from implantation to full term. All calculations happen in your browser.