Due Date Calculator

heart icon due date calculator

Due Date Calculator

Due Date Calculator

Most pregnancies last around 38 weeks from conception.  Typically women ovulate about two weeks after their menstrual cycle starts, so the best way to estimate your due date is to count 40 weeks, or 280 days, from the first day of your last menstrual period.  

Another way to do it is to subtract three months from the first day of your last period and add seven days. So if your last period started on April 11, you’d count back three months to January 11 and then add seven days, which means your due date would be January 18.

This is how your doctor will estimate your due date — and it’s a pretty solid target. But remember: It’s just as normal to deliver a week or two before or after.

Pregnancy Due Date Calculator
Calculation method
📅
📅

Are you pregnant but you’re not sure exactly when you conceived?

You have several options for determining your conception date:

  • An ultrasound is the most accurate way to see how far along your pregnancy is. Ultrasounds provide a detailed look at your baby’s development and will give you a good estimate of how far along your pregnancy is.
  • An online pregnancy calculator can give an estimate of when you conceived based on when your last period was. This method is not as accurate as a confirmation ultrasound.

We offer free ultrasounds at our pregnancy center. Our medical professionals are trained in limited obstetrical ultrasound and provide medical services under the direction and supervision of a licensed physician.

How to Know When You Conceived

In general, women can only conceive when they are ovulating – that is, when their ovaries release a new egg into their fallopian tubes for fertilization. Ovulation usually occurs about two weeks after your menstrual period and lasts for two or three days.

However, not all women have the same cycles of menstruation and ovulation. Some women’s menstrual cycles are irregular. Others have ovulation periods closer to or further from their menstrual period. Some women simply aren’t sure when their last period was. In other words, calculating conception based just on your body cycles can be difficult.

You can also simply try to determine the last time you had sexual intercourse, but this method isn’t totally accurate either. Conception is a process and takes time, and a man’s sperm can actually stay alive inside your body for up to a week after sex. All of these factors can make it hard to know when exactly you conceived.

This is why a pregnancy confirmation ultrasound is the best way to know how far along your pregnancy is and to determine when you conceived. Pregnancy ultrasounds look directly at the development of your growing baby to determine its age and when you likely conceived. This method is much more accurate than date-based calculation.

Your Next Steps

Have Questions?

Please call (856) 374-2445 or text 856-214-1997 Monday through Friday 9am-5pm

en_USEN