Pregnancy Due Date Calculator — How Many Days Until Baby?

A standard pregnancy lasts about 280 days (40 weeks) from the first day of the last menstrual period. But counting 280 days on a calendar is surprisingly tricky — months have different lengths, and keeping track of weeks versus days gets confusing fast.

This calculator does the math for you. Enter your last menstrual period date (LMP) or estimated conception date and instantly see your due date, how many days are left, and a visual timeline of your pregnancy.

Pregnancy is typically divided into three trimesters: the first runs from week 1 through week 12 (about 84 days), the second from week 13 through week 26, and the third from week 27 through week 40 (your due date). Each trimester has distinct milestones — first ultrasound, anatomy scan, glucose test, and more.

Knowing your exact day count helps you schedule important appointments, plan maternity or paternity leave, and prepare for the arrival — especially when coordinating with a partner's work schedule, arranging childcare for older children, or timing a move.

Keep in mind that a "due date" is an estimate. Only about 5% of babies arrive on their exact due date. Most healthy pregnancies deliver between 38 and 42 weeks. This calculator gives you a target to plan around, not a guarantee.