Pregnancy Due Date Calculator

Estimate due date and pregnancy timeline.

Pregnancy due date

First day of last period

Due date

Enter the first day of your last menstrual period.

Pregnancy Due Date Calculator

Estimate your due date from the first day of your last menstrual period using Naegele's rule - adding 280 days (40 weeks). Your doctor may refine this with an ultrasound.

Frequently asked questions

How accurate is the due date?

Only about 1 in 20 babies arrive exactly on the due date; most arrive within two weeks either side. An ultrasound dating scan gives a more precise estimate.

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