Naegele’s rule is under the antepartum chapter of Maternity. Naegele’s rule is pretty simple to calculate, but very easy to make a minor error. Just remember that the result of Naegele’s rule is just an estimation.

Estimating the date of confinement, or estimating date for delivery, can be determined with Naegele’s rule.

In layman’s term, if you want to know when you’re going to give birth, use Naegele’s rule.

Naegele’s rule’s fun fact: Did you know that Naegele’s rule was named after Franz Karl Naegele, a German obstetrician who came up with Naegele’s rule.

Fun NCLEX tips when using Naegele’s rule:

1. Do not think about using leap year. February will always have 28 days no matter what.

2. Each month have different number of days so keep that in mind! April, June, September, and November have 30 days.

3. Calculation is done assuming that the woman has a menstrual cycle of 28 days. The NCLEX is aware that this does not apply to everyone, but with Naegele’s rule, we’re going to assume.

The woman is required to have a regular menstrual cycle of 28 days.

  • Add 7 days to the first day of the last menstrual period
  • Subtract 3 months
  • Add 1 year


  • Last menstrual period: May 1, 2014
  • Add 7 days: May 8, 2014
  • Subtract 3 months
  • Add 1 year – What do you get? Hover below to find out!

Answer: February 8, 2015 is the estimated date of confinement

Silvestri, Linda Anne. “Obstetrical Assessment”Saunders Comprehensive Review for the NCLEX-RN Examination. 5th ed. St. Louis, MO: Saunders Elsevier, 2011. 261. Print.