pregnancy due date calculator
estimate your due date and key milestones from the first day of your last menstrual period.
runs on your device · free · no sign-up
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frequently asked questions
how is the due date calculated?
Naegele's rule adds 280 days (40 weeks) to the first day of your last period, adjusted if your cycle is not 28 days.
how accurate is it?
only about 5% of babies are born on the due date. it is an estimate; a doctor can confirm dating, usually with an ultrasound.
is my data private?
yes. dates are processed in your browser and never stored or sent.