Due Date Calculator
Calculate baby delivery dates and gestational age
Due Date Calculator
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Estimated due date0
Results are estimates only
Formula
Due date = first day of last period + 280 days (adjusted for cycle length)
Data as of
Results are estimates only
FAQ
It uses Naegele's rule: first day of last menstrual period + 280 days (40 weeks), adjusted for actual cycle length.
Yes. If your cycle is longer than 28 days, the tool shifts the due date forward by the extra days for better accuracy.