About Pregnancy Due Date Calculator
Estimate the expected baby delivery date using Naegele’s clinical rule.. Designed for accurate, instantaneous calculations with zero wait time.
Formula
Estimated Due Date = Last Menstrual Period (LMP) + 280 days (40 weeks)
Example Calculation
If LMP was Jan 1, 2026, estimated delivery date is October 8, 2026.
How to Use
- Enter your values into the form fields above.
- The calculation updates immediately in real time.
- Inspect the main summary and secondary breakdowns below.