Health & Fitness

Pregnancy Due Date

Naegele: LMP + 280 days.

First day of LMP

Educational estimates only. Not medical, legal, tax, or financial advice.

Guide: Pregnancy Due Date

What it does

Adds 280 days (40 weeks) from LMP to estimate a due date.

How to use it

Enter the first day of your last menstrual period and calculate.

Formula

Due date ≈ LMP + 280 days (calendar).

Example

If LMP was January 1, a rough due date is around October 8 of the same year (varies by cycle length).

FAQs

Is this my official due date?

Only your clinician can confirm dating with ultrasound and history.

What if my cycles are irregular?

LMP-based estimates are less reliable; use provider-assessed dating.

Why 40 weeks?

It is a conventional obstetric estimate from LMP; not every pregnancy lasts exactly 40 weeks.