2010
#156,044
National surname rank
Recorded bearers 104
First available Census row
Per 100,000 0.04
Very Rare Last name
Castex
A toponymic surname likely of Spanish origin referring to someone from a region called Castex or Casteix.
According to the 2020 US Census Bureau surname tables, roughly 131 Americans carry the last name Castex. That puts it at #146,495 in the national surname ranking, appearing at a frequency of 0.04 per 100,000 people (about 1 in 2,616,445 residents).
This page is the full Name Census profile for the Castex 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
131
1 in 2,616,445
Census rank
#146,495
2020 decennial data
Per 100,000
0.0
Frequency rate
Recorded bearers
114
very rare in the US
Popularity narrative
The Census Bureau recorded 114 bearers of the surname Castex in its 2020 decennial surname file. At a rate of 0.04 per 100,000 residents, it holds the 146495th position in the national surname ranking.
Among Census respondents with the surname Castex, the largest self-reported group is Black at 33.3%. The next largest groups are Hispanic (28.1%) and White (27.2%).
Origin
Meaning and origin of Castex
The surname Castex is of French origin, derived from the Occitan language spoken in southern France. It is believed to have originated in the region of Gascony, specifically around the town of Castets in the department of Landes. The name likely comes from the Occitan word "Castèth," meaning "little castle" or "small fortress."
One of the earliest known records of the name Castex can be found in the "Livre des Hommages" (Book of Homages), a manuscript dating back to the 13th century. This document mentions a certain Petrus de Castex, who was a landowner in the Landes region during that time.
In the 16th century, a notable figure bearing the name Castex was Jean de Castex, a Protestant clergyman and theologian born in Béarn around 1520. He played a significant role in the French Reformation and was a close associate of Theodore Beza, a prominent Calvinist reformer.
During the 17th century, the name Castex appears in various legal documents and records related to the region of Gascony. One such record mentions a Pierre Castex, a merchant from the town of Saint-Sever, who was involved in a land dispute in 1687.
In the 18th century, a notable bearer of the Castex name was Jacques Castex, a French military officer born in Gascony around 1720. He served in the French army during the Seven Years' War and is known for his participation in the Battle of Minden in 1759.
Another significant figure with the surname Castex was Bertrand Castex, a French author and literary critic born in Bordeaux in 1909. He is best known for his works on French literature and his analysis of the works of Marcel Proust. Castex passed away in 1997.
Throughout history, the surname Castex has also been associated with various place names in southern France, such as Castex-d'Armagnac, a commune in the department of Gers, and Castex-Labarède, a commune in the department of Haute-Garonne. These place names likely derive from the same Occitan root as the surname.
Demographics
Ancestry and ethnicity for Castex
Among Census respondents with the surname Castex, the largest self-reported group is Black at 33.3%. The next largest groups are Hispanic (28.1%) and White (27.2%).
The bar chart below shows how Castex 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 Castex surname at the time of the 2020 Census, not any inherent property of the name itself.
- Black or African American33.3% · 38
- Hispanic or Latino28.1% · 32
- White27.2% · 31
- Two or more races10.5% · 12
- Asian and Pacific Islander0.9% · 1
Timeline
Historical Census data for Castex
Castex appears in 2 published Census surname files: 2010, 2020. The cards below show how the name's rank and bearer count changed across each release.
2020
#146,495
National surname rank
Recorded bearers 114
+10 bearers (+9.6%)
Per 100,000 0.04
Rank movement Up 9,549 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2010 | #156,044 | 104 | 0.04 | First available Census row | First available Census row |
| 2020 | #146,495 | 114 | 0.04 | +10 bearers (+9.6%) | Up 9,549 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 Castex 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 | #156,044 | #146,495 | 6.1% |
| Count | 104 | 114 | 9.6% |
| Per 100K | 0.04 | 0.04 | -4.6% |
Between the 2010 and 2020 Census, the number of Castex bearers went from 104 to 114 (+9.6% change). The surname moved up 9,549 positions in the national ranking, going from #156,044 to #146,495.
FAQ
Castex surname: questions and answers
How many people in the U.S. have the surname Castex?
Name Census estimates that about 131 living Americans carry the surname Castex. Using the current population baseline, that works out to roughly 1 in 2,616,445 residents.
How common is Castex?
Castex ranks #146,495 in the 2020 Census surname tables and is classified on this site as "Very Rare." The Census recorded the name at a frequency of 0.04 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 114 people with the surname Castex. That is different from the site's living-bearer estimate (131), which projects the surname's present-day count by applying the Census frequency rate to the current U.S. population.
What does 0.04 per 100,000 actually mean?
It is the Census Bureau's normalized frequency measure. A rate of 0.04 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 Castex.
Has Castex become more or less common over time?
Between 2010 and 2020, the surname Castex went from 104 recorded bearers to 114. That is an increase of 10 (+9.6%). In the national ranking it rose from #156,044 to #146,495.
What does the Census say about the background of Castex?
Among Census respondents with the surname Castex, the largest self-reported group is Black at 33.3%. The next largest groups are Hispanic (28.1%) and White (27.2%). 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?
Black is the largest self-reported group for the surname Castex in the 2020 Census, accounting for 33.3% (38 people in the source table).
What is the full ancestry breakdown?
Castex appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are Black (33.3%), Hispanic (28.1%), White (27.2%). 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 Castex (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 Castex mean?
A toponymic surname likely of Spanish origin referring to someone from a region called Castex or Casteix. 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 Castex (0.04 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 Castex?
For a quick modern estimate, our sister site HowManyOfMe.org answers that in one glance, with the living-bearer count front and centre.