Pregnancy Due Date Calculator

Calculate your due date, current pregnancy week, trimester, and important milestones

Pregnancy Information

Quick Examples

Enter Your Information

Select a calculation method and enter the relevant date to estimate your due date and pregnancy timeline.

About Pregnancy Due Date Calculation

What Is a Due Date Calculator?

A pregnancy due date calculator estimates your expected delivery date based on key dates such as your last menstrual period (LMP), conception date, or IVF transfer date. The standard pregnancy lasts about 280 days (40 weeks) from the first day of your last period.

How Is It Calculated?

For LMP-based calculation, Naegele's rule adds 280 days (40 weeks) to the first day of your last menstrual period. For conception-based calculation, 266 days (38 weeks) are added. For IVF, the transfer date is adjusted by the embryo age at transfer and then 266 days are added.

Important Disclaimer

This calculator provides an estimate. Only about 5% of babies arrive on their exact due date. Your healthcare provider will give you a more accurate assessment based on ultrasounds and clinical examinations.

Pregnancy Due Date FAQ

How accurate is the due date estimate?

LMP-based estimates are accurate to within about 1-2 weeks for most women. Ultrasound dating in the first trimester is more precise, especially if your cycle length varies.

What if I don't know my last menstrual period date?

If you're unsure of your LMP, an early ultrasound is the most reliable way to determine gestational age. You can also use the conception date if you know it, or the IVF transfer date if applicable.

Can my due date change during pregnancy?

Your doctor may adjust your due date based on ultrasound measurements, especially during the first trimester. However, after the first trimester, due dates are rarely changed significantly.

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