Health Tools
Pregnancy due date calculator
Estimate your due date from the first day of your last menstrual period, using Naegele’s rule (last period plus 280 days).
Frequently asked questions
How is my due date calculated?
The calculator uses Naegele’s rule: it adds 280 days (40 weeks) to the first day of your last menstrual period to estimate your due date.
How accurate is the due date estimate?
It is an estimate — only about 1 in 20 babies arrive on their exact due date. An early ultrasound gives your care provider a more precise date.
What if I don’t know my last period date or have irregular cycles?
The estimate is less reliable with irregular cycles or an unknown last period. Your healthcare provider can date the pregnancy accurately with an ultrasound.
Is the information I enter private?
Yes. The calculation runs entirely in your browser. Evecare never sees, stores, or transmits anything you enter.