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Pregnancy Due Date
Estimate a due date and gestational age from your last period.
Educational estimate only — not a diagnosis. Values are calculated in your browser and never stored. Discuss your results with a licensed clinician.
Frequently asked questions
How is the due date estimated?
It adds 280 days (40 weeks) to the first day of your last period, assuming a 28-day cycle. An ultrasound gives a more precise date.
How accurate is it?
It's a good estimate for regular cycles, but only about 1 in 20 babies arrive exactly on the due date. Your provider may adjust it after a scan.
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