Pregnancy Due Date Calculator

Estimate your pregnancy due date and trimester timeline based on your last menstrual period.

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About Due Date Calculation

Due dates are estimated using Naegele's rule: add 280 days (40 weeks) to the first day of the last menstrual period (LMP). The cycle length adjustment accounts for longer or shorter ovulation timing. Only about 5% of babies arrive on their exact due date.

About This Tool

The Pregnancy Due Date Calculator helps expecting mothers estimate their due date and track the progression of their pregnancy.

Simply enter the first day of your last menstrual period to receive an estimated delivery date and a breakdown by trimester. The tool also provides gestational age information.

This free browser-based calculator is perfect for tracking pregnancy milestones without requiring any sign-up or data sharing.

Frequently Asked Questions