Enter the first day of your last menstrual period, the conception date, or the expected due date - the calculator fills in the rest and shows key milestones.
The calculator estimates dates from the first day of your last menstrual period, conception date or expected due date. Pregnancy dating is usually counted from the first day of the last menstrual period.
A due date is an estimate, not a guaranteed birth date. Only a minority of babies are born exactly on their due date. Early ultrasound dating may adjust the estimate if dates are uncertain.
Clinicians use the first day of the last menstrual period because ovulation and conception are often difficult to date exactly. This gives a consistent way to estimate gestational age.
Yes. If you know the likely conception date, the calculator can estimate your pregnancy week and due date from that date. Gestational age is still usually about two weeks ahead of embryo age.
Confirm your dates with a midwife, OB-GYN, GP or maternity provider, especially if your cycles are irregular, your last period date is uncertain, you conceived with fertility treatment or your scan dates differ.