Pregnancy Due Date Calculator

First Day of Last Menstrual Period (LMP)

Estimated Due Date

October 22, 2026

Conception Date

January 29, 2026

Gestational Age

27 weeks, 5 days

Current Trimester

Second Trimester

What Is Naegele's Rule?

Naegele's rule is a standard method of calculating the estimated date of delivery (EDD) by adding 1 year, subtracting 3 months, and adding 7 days to the first day of the last menstrual period (LMP).

Frequently Asked Questions

How is a pregnancy due date calculated?

Naegele's rule calculates due date by adding 280 days (40 weeks) to the first day of your last menstrual period (LMP).

How accurate is an estimated due date?

Only about 5% of babies are born on their exact due date. Most births occur within 2 weeks before or after.

What are the three trimesters?

First trimester: Weeks 1–12; Second trimester: Weeks 13–27; Third trimester: Weeks 28–40+.

Can conception date be used instead of LMP?

Yes. If conception date is known, add 266 days (38 weeks) to find the estimated due date.

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