Estimate a pregnancy due date from the first day of the last menstrual period, an estimated conception date or an IVF embryo transfer date. Each method uses a different standard day offset, and IVF estimates also account for whether a day-3 or day-5 embryo was transferred. The calculator accepts recent reference dates and presents a calendar estimate, not a medical diagnosis. A clinician may revise pregnancy dating using ultrasound, cycle history and other health information.
Choose whether your reference is an LMP, conception or IVF transfer date.
Enter the reference date and select the embryo age when IVF is used.
Read the estimated due date and gestational-age estimate as informational only.
LMP estimate: First day of last period + 280 days
Conception estimate: Estimated conception + 266 days
IVF estimate: Transfer date + (266 − embryo age in days)
Is the due date exact?
No. It is a calendar estimate. Only a qualified clinician can advise on pregnancy dating and care based on your history and examinations.
Why does IVF use embryo age?
The estimated date accounts for the embryo's developmental age at transfer. The calculation shown uses a day-3 or day-5 transfer convention.