Enter your last menstrual period (LMP) or conception date to get your estimated due date, current week, and pregnancy milestones.
From LMP: We add 280 days (40 weeks) to the first day of your last menstrual period. This follows Naegele's rule, the standard medical calculation.
From Conception: We add 266 days (38 weeks) to your conception or IVF transfer date, then adjust for gestational age.
Note: Only about 5% of babies arrive exactly on their due date. Most babies arrive within 2 weeks before or after. Always consult your healthcare provider for personalized medical advice.
To calculate your due date, enter the first day of your last menstrual period (LMP) in the calculator above. The tool will add 280 days (40 weeks) to give you your estimated due date. Alternatively, if you know your conception date or IVF transfer date, you can use the "From Conception Date" tab for a more precise calculation.
The calculator uses the standard Naegele's rule (adding 280 days to your LMP), which is the same method used by healthcare providers. However, only about 5% of babies arrive exactly on their due date. Most babies arrive within 2 weeks before or after the estimated due date. Your actual delivery date can be affected by factors like cycle length, conception date accuracy, and individual variation.
LMP (Last Menstrual Period) calculation adds 280 days (40 weeks) to the first day of your last period, while conception date calculation adds 266 days (38 weeks) to your known conception or IVF transfer date. The LMP method is more commonly used because most women know their last period date, but conception date can be more accurate if you know the exact date of conception.
Pregnancy is divided into three trimesters: First trimester is weeks 1-13, second trimester is weeks 14-27, and third trimester is weeks 28-40 (or until delivery). The calculator automatically shows which trimester you're currently in based on your due date calculation.
The first ultrasound is typically performed around week 12 of pregnancy, at the end of the first trimester. This is called the dating scan or nuchal translucency scan. Some women may have an earlier ultrasound around 6-8 weeks to confirm pregnancy and check the heartbeat. Your healthcare provider will schedule ultrasounds based on your specific situation.
A full-term pregnancy is considered to be 37 weeks or later. Babies born at 37 weeks or beyond are generally fully developed and ready for life outside the womb. The ideal time for delivery is between 39-40 weeks, but any time after 37 weeks is considered safe and full term.
Yes! Click on the "From Conception Date" tab and enter your IVF embryo transfer date. The calculator will adjust for the age of the embryo transferred (typically adding 266 days) to give you an accurate due date. This method is often more precise than LMP for IVF pregnancies.