Pregnancy Calculator

Remember, the more you know about your own monthly cycle the more accurate the calculator will be. If you are trying to fall pregnant, read our section on getting pregnant.

How Do You Calculate Your Due Date?

Have you ever wanted to know how your doctor or health care provider calculates your estimated due date and age of your baby? Well, it is actually a really simple process:

You add 280 days to the first day of your last menstrual period, or LMP

It is really as simple as that. The 280-day cycle works on the typical 266-day gestation period for humans. We get 280 days because we add 14 days, which is the average time span for when you would have ovulated.

Obviously this is just an average, but with our calculator the 14 days can be changed for what your actual Luteal Phase, or to what your actual ovulation period actually is, and this makes it extremely useful, as the more you know about your monthly cycle, the more accurate your calculations will be.

The more you know about your monthly cycle the more accurate our calculator will be. So as mentioned in the conception basics, it is a good idea to track your monthly cycles for a few months before hand.

Of course not all pregnancies are planned, but if your monthly cycle is more regular, then you should have no problems using our calculator.

Don't forget that you can use these calculations in conjunction with our pregnancy calendar.