How do I calculate my pregnancy due date?
Do you know your due date? Find out when you're due, how many weeks along you are, and your conception date.
When will implantation happen?
This calculator also lets you know the day when you can expect implantation (the day that the embryo attaches to the lining of the uterus).
How do I calculate when to have sex to get pregnant?
Enter the exact date of the first day of your last menstrual period and we will calculate the best days to have sex. The calculator will let you know the 5-6 fertile days to improve your chances of getting pregnant.
How many weeks am I?
Enter first your last period or due date, and we will tell you automatically how far along you are today. If you want to know how far along you are on a certain date, enter that date next and we will calculate next how far along you are.
Exact calculation of the due date
Calculating an accurate due date is an important first step in pregnancy. The calculation of the estimated due date (EDD) is based on the day of the date of ovulation and fertilization. The EDD can be calculated by adding 266 days to the day of ovulation/fertilization.
Find out why estimating the correct pregnancy due date is important.
The first step is to know the first day of your last menstrual period and the length of your menstrual cycle. Enter the date of the first day of the last menstrual period and your average cycle length. Alternatively, you can also enter the day of ovulation, the weeks and days of the pregnancy on ultrasound, or the IVF egg or embryo transfer date.
The due date calculator will then calculate the exact date the baby will be due, as well as other important events such as the date of implantation, when the baby will start moving and dates for important tests like amniocentesis, ultrasound, or glucose screen.
What is the conception date?
"Conception" has different definitions: One definition of conception is that conception is the same day as the day of fertilization, the time after you ovulate and when the sperm meets the egg! Another definition is that conception is the same day as the day of implantation which happens on average 9 days after ovulation/fertilization with a range of 6-12 days.
What is the last menstrual period (LMP)?
The LMP is the date of the first day of your last menstrual period. It is the first day that your last menstrual cycle began. It is the first day that you see bright red blood, not just a little brown spotting. You should keep track of your LMP each month, either electronically, online, or at home in a calendar. That is the date you use when entering the LMP.
Am I ovulating?
If you don't know the exact date of ovulation, then use our ovulation calculator to the approximate first day of your last menstrual period in a 28-day cycle. If your cycles are longer or shorter than 28 days, then the day of ovulation may change, and this calculator takes that into consideration when calculating your estimated due date.
You can also use this calculator as a reverse due date calculator to find out when you became pregnant. Just enter your due date and we will calculate the estimated day of conception. In addition, you'll get a range of dates that you may have become pregnant.
How can a conception calculator be used?
Conception calculator use differs from one woman to the next. If a woman has had unprotected sex with more than one man, she may want to use the conception calculator to give her an idea who the father may be. However, if there is no menstrual cycle between the bouts of unprotected sex, a conception calculator will not effectively reveal paternity. Only a paternity test will reveal the true father of the child in this case.
How accurate is a conception calculator?
There is no way of knowing the exact date of conception unless a woman tracks her cycle and has unprotected intercourse only once per cycle. However, you can make an estimated guess! The conception calculator will give you an estimated date of the probable time when conception occurred.
Could the conception calculator be wrong?
Yes, a conception calculator can be wrong. Ultrasounds can also be wrong as can home pregnancy tests. There is no perfect system for estimating an exact conception date unless intercourse happened only once between menstrual cycles.
Why does the ultrasound give a different due date from the conception calculator?
A conception calculator uses the first day of the last menstrual cycle to determine the probable date of conception. Ultrasound uses the size of the fetus to estimate gestational age. Ultrasound dating can change throughout pregnancy based on the size of the fetus, but the conception calculator will always offer the same probable date of conception based on the last menstrual cycle and length of the average menstrual cycle.
What is the difference between an online conception calculator and the “wheel” conception calculator that a doctor uses?
There is no difference between the two. The doctor uses the first day of your last menstrual cycle to estimate due date and conception date in much the same way the online conception calculator works.
All results are based on the input, so you need to know the accurate first day of their last menstrual cycle to achieve the best and most reliable results.