Pregnancy calculator

Calculate your due date with our pregnancy calendar: Which week are you in?

To calculate how far along your pregnancy is, you need to know the first day of your last menstrual period.
Baby Journey’s pregnancy calendar can automatically calculate your due date based on this information. So, as soon as you’ve gotten a positive pregnancy test, we can be the first to give you an approximate date to start from — showing when your baby is likely to arrive.

If you want a better understanding of how due dates are calculated in practice, you can count months (each counted as 28 days) or pregnancy weeks (7 days) from the first day of your last period. This way, you can figure out roughly how far along you are.

You’ll probably notice that 28 days × 9 months (the typical length people refer to) doesn’t equal 280 days, which is the standard duration of a pregnancy. That’s because the “9 months” of pregnancy we usually talk about actually start from week 4 — around the time you find out you’re pregnant.

This means that if you count from the first day of your period, you’re actually pregnant for 10 months!

By calculating your due date, you’ll get an idea of when your baby might arrive, but very few babies are born exactly on that estimated date. The due date is more of an indication of when your baby is likely ready to meet the world.

Your due date might also shift a few days forward or backward after your ultrasound scan, as healthcare professionals can measure the fetus to determine the gestational week more precisely. Your date can also change depending on whether you have a longer or shorter menstrual cycle than average.