Due Date Calculator

Planning your baby shower, maternity photoshoots, and nursery decoration timelines.

Drafting your maternity or paternity leave requests for your employer with realistic dates.

Budgeting for major baby purchases like car seats, strollers, and diapers before the birth month.

Tracking your weekly pregnancy milestones so you know exactly when your baby starts developing fingernails, eyelashes, and hiccups!

Why do I keep getting different due dates from different calculators?

It is completely normal to see slightly different dates depending on the tool you use. Some simple calculators assume every woman has a perfect 28-day cycle and ovulates on day 14, while more advanced calculators (like ours!) let you adjust for your actual cycle length. Additionally, your doctor might adjust your due date after an early ultrasound scan if the baby is measuring larger or smaller than expected. Trust your doctor's ultrasound dating above all, as it's the most accurate way to see how your baby is growing.

What if I don't know the exact date of my last period?

Don't panic—plenty of parents-to-be don't have this date memorized! If you aren't sure, you can estimate based on your best guess, or wait for your first prenatal doctor's appointment. During your first trimester, your doctor will perform a dating ultrasound to measure the baby's crown-to-rump length. This measurement is incredibly precise and can pin down your due date within a margin of just 5 to 7 days.

Does my due date mean my baby will definitely be born on that day?

Not at all, so don't count on a birth day party on that exact date! Only about 5% of babies actually arrive on their calculated due date. Think of your due date as a helpful anchor point rather than a promise. Most babies make their grand entrance anywhere from two weeks before to two weeks after their estimated date, which is perfectly healthy and normal.

How does my cycle length change my due date?

Your cycle length determines when you actually ovulate and conceive. The standard pregnancy calculation assumes you ovulate 14 days after your period starts. If you have a longer cycle (say, 35 days), you likely ovulated later, which pushes your due date back. If you have a shorter cycle, you ovulated earlier, which pulls your due date forward. Adjusting for this ensures you don't worry unnecessarily about your baby being 'early' or 'late'!

Why does my doctor count my pregnancy from before I was actually pregnant?

It sounds a bit silly, but doctors count your pregnancy from the first day of your last period because it is a concrete, easily trackable date. Pinpointing the exact moment of conception is incredibly difficult, as sperm can live inside the body for several days before fertilizing an egg. By starting the clock at your last period, medical professionals have a consistent standard to measure fetal growth milestones across all pregnancies.

Can my due date change later in my pregnancy?

Yes, but it is less common in the later trimesters. If an early first-trimester ultrasound differs from your period-based due date by more than a week, your doctor will likely update your official due date. However, doctors rarely change your due date based on late-pregnancy ultrasounds because babies grow at different rates in the second and third trimesters, making size-based dating much less reliable.

How do I plan my maternity leave using this date?

When planning your leave, it is best to build in a little bit of a buffer. Since babies love to surprise us, aiming to wrap up work about a week or two before your official due date is a great strategy if your budget and workplace allow. This gives you some quiet time to rest, nest, and mentally prepare before your little one arrives. Always discuss your plans early with your employer so everyone is on the same page when the big day comes.