Genealogy: 1820 Census birth year reference chart

1820_Cenus_Birth_Reference_ChartBy 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 1820 U.S. Federal Population Census.

Learn more about information about age found in the census:

1820 U.S. Census birth year reference chart
In the 1820 US Population Census, learn the the approximate corresponding birth years associated with the age groupings provided.  This census allowed 12 months to be completed.  The first family would have been recorded in August 7, 1820 and the last family on September 7, 1821. The numbers shown in the categories did not distinguish between who was family and any others who were in the household such as relatives, friends, employees, visitors, boarders, servants.

Note: No matter when the census taker came, he was to record who was in the house as of August 7, 1820.  If a child was born after this date they were not to be counted.  If a person died before this date, they were not to be counted.   It is very probable the census taker just recorded who was there the day he arrived.

Important: Note the age column heading for males 16-18 and 16 & under 26.  Any male listed in the 16-18 would also appear in the 16 & under 26. Do not double count males. The reason that there was even a 16-18 category is because the U.S. Government wanted to see how many males would be available for military service.

Age calculated as of August 7, 1820 and does not allow for the 13 month variance.

Free White Males
Age CategoryBorn Between Years
10 and under (0-9)1810-1820
10 & under 16 (10-15)1810-1805
16-18 (16-18)1804-1802
16 & under 26 (16-25)1804-1795
26 & under 45 (26-44)1794-1776
45 & up (45+)1775 & before
Free White Females
Age CategoryBorn Between Years
10 and under (0-9)1810-1820
10 & under 16 (10-15)1810-1805
16 & under 26 (16-25)1804-1795
26 & under 45 (26-44)1794-1776
45 & up (45+)1775 & before
Slaves (Male and Female)
Age CategoryBorn Between Years
14 & under (0-13)1807-1820
14 & under 26 (14-25)1806-1795
26 & under 45(26-44)1794-1776
45 & up (45+)1775 & before
Free Colored Persons (Male and Female)
Age CategoryBorn Between Years
14 & under (0-13)1807-1820
14 & under 26 (14-25)1806-1795
26 & under 45(26-44)1794-1776
45 & up (45+)1775 & before