Genealogy: 1920 Census birth year reference chart

census birth yearBy Barry J. Ewell
As you track your ancestor through the U.S. Federal Population Censuses, you can use age to help you

  • Identify individual members of the family
  • Provide clues to confirm I have the right person/family unit as you search each census
  • Provide clues as to relationship in the family
  • Provide clues if I have the right female when surnames change through marriage
  • Provide clues when people use nicknames and other name variations from one census to the next

I have prepared a birth year reference chart for each census to help you identify an estimated birth year for each ancestor.  This article will focus on the 1920 U.S. Federal Population Census.

Learn more about information about age found in the census:

1920 U.S. Census birth year reference chart
In Column 11 of the 1920 US Population Census, learn the age of each member of the household.  The following chart will provide the approximate corresponding birth year for the age provided.

Age calculated as of January 1, 1920.

AgeBirth YearAgeBirth YearAgeBirth Year
Mar 0/121920281892671853
Feb 1/121920291891681852
Jan 2/121920301890691851
Dec 3/121920311889701850
Nov 4/121919321888711849
Oct 5/121919331887721848
Sep 6/121919341886731847
Aug 7/121919351885741846
Jul 8/121919361884751845
Jun 9/121919371883761844
May 10/121919381882771843
Apr 11/121919391881781842

Census taker instructions for age on 1930 Census
The following are the exact instructions given to census taker (enumerator):

122. Column 11. Age at last birthday.- This question calls for the age in completed years at last birthday. Remember, however, that the age question, like all other questions on the schedule, relates to January 1, 1920. Thus a person whose exact age on January 1, the census day, is 17 years, 11 months, and 25 days should be returned simply as 17, because that is his age at last birthday prior to January 1, although at the time of your visit he may have completed 18 years.

123. Age in round numbers.-In many cases person will report the age in round numbers, like 30 or 45, or “about 30” or “about 45,” when that is not the exact age. Therefore, when an age ending in 0 or 5 is reported, you should ascertain whether it is the exact age. If, however, it is impossible to get the exact age, enter the approximate age rather than return the age as unknown.

124. Ages of children.-Take particular pains to get the exact ages of children. In the case of a child not 5 years old, the age should be given in completed months, expressed as twelfths of a year. Thus the age of a child 3 months old would be entered as 3/12, a child 7 months old as 7.12, a child 1 year and 3 months old a 1 3/12, a child exactly 3 years old as 3 0/12, a child 3 years and 1 month old as 3 1/12, etc. If a child is not yet a month old, enter the age as 0/12. But note again that this question should be answered with reference to January 1. For instance, a child who is just a year old on the 5th of January 1920, should nevertheless be returned as 11.12, because that is its age in completed months on January 1.