2000
#123,314
National surname rank
Recorded bearers 129
First available Census row
Per 100,000 0.05
Very Rare Last name
Decair
From the French, meaning "of/from Cair" which is the old name for Cherbourg, France.
According to the 2020 US Census Bureau surname tables, roughly 118 Americans carry the last name Decair. That puts it at #154,182 in the national surname ranking, appearing at a frequency of 0.03 per 100,000 people (about 1 in 2,904,698 residents).
This page is the full Name Census profile for the Decair surname. You will find the Census Bureau frequency data, a multi-census history view, an ancestry and ethnicity breakdown based on self-reported demographics, the name's meaning and origin where available, and answers to the most common questions people ask about this surname.
Bearers in the US
118
1 in 2,904,698
Census rank
#154,182
2020 decennial data
Per 100,000
0.0
Frequency rate
Recorded bearers
103
very rare in the US
Popularity narrative
The Census Bureau recorded 103 bearers of the surname Decair in its 2020 decennial surname file. At a rate of 0.03 per 100,000 residents, it holds the 154182nd position in the national surname ranking.
Among Census respondents with the surname Decair, the largest self-reported group is White at 80.6%. The next largest groups are Hispanic (11.7%) and American Indian/Alaska Native (3.9%).
Origin
Meaning and origin of Decair
The surname DECAIR is of French origin, derived from the Old French word "decair," which means "to decline" or "to decay." The name likely originated in the late Middle Ages, around the 13th or 14th century, in the northern regions of France, particularly in Normandy.
One of the earliest recorded instances of the DECAIR surname can be found in the "Livre des Bourgeois de Rouen," a historic record of the citizens of Rouen, Normandy, dating back to the 14th century. In this document, a certain Jean DECAIR is mentioned as a merchant in the city.
During the 15th century, the name appeared in various municipal records and tax rolls in the regions of Picardy and Île-de-France. It is believed that some members of the DECAIR family may have been involved in agriculture or land management, as the name could have been associated with the decline or decay of crops or land fertility.
In the 16th century, the DECAIR surname gained more prominence, with notable individuals such as Pierre DECAIR (1520-1587), a renowned scholar and philosopher from Paris. His work, "De Rerum Natura," explored the natural world and the human condition.
Another notable figure was Jeanne DECAIR (1575-1642), a French noblewoman from Normandy who played a significant role in the religious and political affairs of her time. She was known for her patronage of the arts and her support of the Catholic Church.
In the 17th century, the DECAIR surname spread to other parts of Europe, particularly to the Low Countries (modern-day Belgium and the Netherlands), where some members of the family settled and established themselves as merchants and traders.
One example is Jacques DECAIR (1630-1698), a Dutch merchant and entrepreneur who founded a successful trading company in Amsterdam. His descendants continued to play a prominent role in the city's commercial and cultural life.
Another notable figure from this period was Élisabeth DECAIR (1685-1752), a French writer and philosopher from Paris. Her works explored the themes of human nature, morality, and the pursuit of knowledge.
As the centuries progressed, the DECAIR surname continued to be found throughout France and other parts of Europe, with some individuals achieving success in various fields, including the arts, sciences, and politics.
Demographics
Ancestry and ethnicity for Decair
Among Census respondents with the surname Decair, the largest self-reported group is White at 80.6%. The next largest groups are Hispanic (11.7%) and American Indian/Alaska Native (3.9%).
The bar chart below shows how Decair bearers described their own race and ethnicity on the 2020 Census form. The Census Bureau groups responses into six broad categories: White, Black or African American, Hispanic or Latino, Asian and Pacific Islander, American Indian and Alaska Native, and Two or More Races. When a category has too few respondents for a given surname, the Bureau suppresses the figure to protect individual privacy, which is why some names show fewer than six slices.
Percentages are shown for every Census year so the breakdown stays comparable over time. When the source file also includes raw headcounts, Name Census shows those alongside the percentages in the legend.
Keep in mind that these are self-reported numbers. A person's surname does not determine their race or ethnicity, and the distribution you see here reflects the specific population who happened to carry the Decair surname at the time of the 2020 Census, not any inherent property of the name itself.
- White80.6% · 83
- Hispanic or Latino11.7% · 12
- American Indian and Alaska Native3.9% · 4
- Two or more races3.9% · 4
Timeline
Historical Census data for Decair
Decair appears in 3 published Census surname files: 2000, 2010, 2020. The cards below show how the name's rank and bearer count changed across each release.
2010
#140,157
National surname rank
Recorded bearers 119
-10 bearers (-7.8%)
Per 100,000 0.04
Rank movement Down 16,843 places
2020
#154,182
National surname rank
Recorded bearers 103
-16 bearers (-13.4%)
Per 100,000 0.03
Rank movement Down 14,025 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2000 | #123,314 | 129 | 0.05 | First available Census row | First available Census row |
| 2010 | #140,157 | 119 | 0.04 | -10 bearers (-7.8%) | Down 16,843 places |
| 2020 | #154,182 | 103 | 0.03 | -16 bearers (-13.4%) | Down 14,025 places |
For 2020, the Census Bureau published race and Hispanic-origin columns as counts rather than percentages. Name Census converts those counts back into shares so the ancestry section stays comparable with the older surname files.
Year on year
2010 vs 2020 Census
How has the Decair surname changed between Census years? The chart shows bearer count side by side, and the table compares rank, count, and frequency.
Census year comparison
20102020
| Metric | 2010 | 2020 | Change |
|---|---|---|---|
| Rank | #140,157 | #154,182 | -10.0% |
| Count | 119 | 103 | -13.4% |
| Per 100K | 0.04 | 0.03 | -13.9% |
Between the 2010 and 2020 Census, the number of Decair bearers went from 119 to 103 (-13.4% change). The surname moved down 14,025 positions in the national ranking, going from #140,157 to #154,182.
FAQ
Decair surname: questions and answers
How many people in the U.S. have the surname Decair?
Name Census estimates that about 118 living Americans carry the surname Decair. Using the current population baseline, that works out to roughly 1 in 2,904,698 residents.
How common is Decair?
Decair ranks #154,182 in the 2020 Census surname tables and is classified on this site as "Very Rare." The Census recorded the name at a frequency of 0.03 per 100,000 residents, which is about 0 people out of every 100,000.
How many people with this surname were counted in the Census?
The raw 2020 Census file counted 103 people with the surname Decair. That is different from the site's living-bearer estimate (118), which projects the surname's present-day count by applying the Census frequency rate to the current U.S. population.
What does 0.03 per 100,000 actually mean?
It is the Census Bureau's normalized frequency measure. A rate of 0.03 per 100,000 means that if you picked a random group of 100,000 U.S. residents, you would expect about 0 of them to have the surname Decair.
Has Decair become more or less common over time?
Between 2010 and 2020, the surname Decair went from 119 recorded bearers to 103. That is a decrease of 16 (-13.4%). In the national ranking it fell from #140,157 to #154,182.
What does the Census say about the background of Decair?
Among Census respondents with the surname Decair, the largest self-reported group is White at 80.6%. The next largest groups are Hispanic (11.7%) and American Indian/Alaska Native (3.9%). These figures come from the 2020 Census Bureau surname tables, based on how respondents described their own race and ethnicity.
Which group reports this surname most often?
White is the largest self-reported group for the surname Decair in the 2020 Census, accounting for 80.6% (83 people in the source table).
What is the full ancestry breakdown?
Decair appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are White (80.6%), Hispanic (11.7%), American Indian/Alaska Native (3.9%). For 2020, the source file also published raw headcounts for each group, which is why this page can show both percentages and counts in the ancestry section.
Is this page using the latest Census data?
Yes. This page is using the latest surname file currently loaded on Name Census, which is 2020. The historical section above also keeps any older Census surname entries we have for Decair (2000, 2010, 2020).
Does the Census include every surname?
No. The Census Bureau only publishes surnames that appeared at least 100 times in a given decennial Census. That means very rare surnames are excluded entirely, and a surname can appear in one Census release but disappear from a later one if it falls below the reporting threshold.
Why don't the ancestry percentages always add up to exactly 100%?
There are two main reasons: rounding and suppression. The Census Bureau rounds published values, and it may suppress very small cells to protect privacy. For 2020, the Bureau also published raw group counts rather than direct percentages, so Name Census converts those counts back into shares for comparability across census years.
What does Decair mean?
From the French, meaning "of/from Cair" which is the old name for Cherbourg, France. The fuller origin note on this page goes into more detail.
Where does the surname data come from?
All surname statistics on Name Census are drawn from the US Census Bureau's decennial surname frequency tables. These files list every surname that appeared 100 or more times in the 2020 Census, along with a count, a per-100,000 rate, and a self-reported demographic breakdown. You can read the full explanation on our methodology page.
How does Name Census estimate living bearers?
For surnames, Name Census does not age cohorts the way it does for first names. Instead, it takes the Census Bureau's published frequency for Decair (0.03 per 100,000) and applies that rate to the current U.S. resident population to estimate how many living Americans have the surname today.
How many Americans have the surname Decair?
For a quick modern estimate, our sister site HowManyOfMe.org answers that in one glance, with the living-bearer count front and centre.