About the Pregnancy Calculator
This pregnancy calculator estimates a due date, current week, trimester, and key date ranges from the date information you provide.
How to Use It
Choose the calculation method, enter the matching date, and select Calculate. If you use the last menstrual period method, the cycle length can adjust the estimate.
How Pregnancy Weeks Are Counted
Pregnancy is usually counted from the first day of the last menstrual period, even though conception commonly happens about two weeks later.
IVF Transfer Dates
For IVF, the estimate uses the transfer date and embryo age. Day 3, day 5, and day 6 transfers have different due date offsets.
Why Due Dates Are Estimates
A due date is a planning estimate, not a guaranteed delivery date. Early ultrasound dating and clinical care can provide more personalized timing.
Clinical Limits and Source
This tool cannot diagnose pregnancy, confirm gestational age, or replace prenatal care. A clinician may use menstrual history, ultrasound, and other information to establish or revise timing. The estimate follows common date-counting conventions summarized in the ACOG due-date guidance. Contact your maternity-care team for symptoms, timing concerns, or urgent care needs.