2010
#136,449
National surname rank
Recorded bearers 123
First available Census row
Per 100,000 0.04
Very Rare Last name
Castanaza
A surname originating from Spain, derived from the Spanish word "castaña" meaning chestnut.
According to the 2020 US Census Bureau surname tables, roughly 136 Americans carry the last name Castanaza. That puts it at #142,788 in the national surname ranking, appearing at a frequency of 0.04 per 100,000 people (about 1 in 2,520,252 residents).
This page is the full Name Census profile for the Castanaza 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
136
1 in 2,520,252
Census rank
#142,788
2020 decennial data
Per 100,000
0.0
Frequency rate
Recorded bearers
119
very rare in the US
Popularity narrative
The Census Bureau recorded 119 bearers of the surname Castanaza in its 2020 decennial surname file. At a rate of 0.04 per 100,000 residents, it holds the 142788th position in the national surname ranking.
Among Census respondents with the surname Castanaza, the largest self-reported group is Hispanic at 97.5%. The next largest groups are White (2.5%).
Origin
Meaning and origin of Castanaza
The surname Castanaza has its origins in Spain, dating back to the 15th century. It is believed to have derived from the Spanish word "castaña," which means "chestnut," and "aza," which is a diminutive suffix. This suggests that the name may have initially referred to someone who lived near a chestnut tree or grove.
One of the earliest recorded instances of the name can be found in the Catalonian town of Tortosa, where a man named Juan Castanaza was mentioned in a document from 1487. The name also appears in various records from the Kingdom of Aragon during the 16th century, indicating that it was relatively widespread in that region.
In the 17th century, the Castanaza family had a prominent presence in the city of Valencia. Notably, a certain Pedro Castanaza (1621-1687) was a respected scholar and author who wrote several treatises on theology and philosophy. His works were widely read and influential during that time period.
The name Castanaza also appears in historical records from the Basque Country, particularly in the town of Bilbao. One notable figure was Ignacio Castanaza (1745-1812), a merchant and ship owner who played a significant role in the region's maritime trade.
In the 19th century, a branch of the Castanaza family settled in the Canary Islands. One of their descendants, Francisco Castanaza (1854-1932), became a renowned artist known for his landscape paintings depicting the islands' stunning scenery.
Another notable figure was María Castanaza (1879-1957), a pioneering educator from Andalusia who established several schools for underprivileged children. Her efforts were instrumental in promoting literacy and education in rural communities during her lifetime.
While the surname Castanaza is not among the most common in Spain today, it has a rich and diverse history spanning several centuries and regions. The name continues to be carried forward by families with deep roots in various parts of the country.
Demographics
Ancestry and ethnicity for Castanaza
Among Census respondents with the surname Castanaza, the largest self-reported group is Hispanic at 97.5%. The next largest groups are White (2.5%).
The bar chart below shows how Castanaza 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 Castanaza surname at the time of the 2020 Census, not any inherent property of the name itself.
- Hispanic or Latino97.5% · 116
- White2.5% · 3
Timeline
Historical Census data for Castanaza
Castanaza 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
#142,788
National surname rank
Recorded bearers 119
-4 bearers (-3.3%)
Per 100,000 0.04
Rank movement Down 6,339 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2010 | #136,449 | 123 | 0.04 | First available Census row | First available Census row |
| 2020 | #142,788 | 119 | 0.04 | -4 bearers (-3.3%) | Down 6,339 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 Castanaza 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 | #136,449 | #142,788 | -4.6% |
| Count | 123 | 119 | -3.3% |
| Per 100K | 0.04 | 0.04 | -0.5% |
Between the 2010 and 2020 Census, the number of Castanaza bearers went from 123 to 119 (-3.3% change). The surname moved down 6,339 positions in the national ranking, going from #136,449 to #142,788.
FAQ
Castanaza surname: questions and answers
How many people in the U.S. have the surname Castanaza?
Name Census estimates that about 136 living Americans carry the surname Castanaza. Using the current population baseline, that works out to roughly 1 in 2,520,252 residents.
How common is Castanaza?
Castanaza ranks #142,788 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 119 people with the surname Castanaza. That is different from the site's living-bearer estimate (136), 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 Castanaza.
Has Castanaza become more or less common over time?
Between 2010 and 2020, the surname Castanaza went from 123 recorded bearers to 119. That is a decrease of 4 (-3.3%). In the national ranking it fell from #136,449 to #142,788.
What does the Census say about the background of Castanaza?
Among Census respondents with the surname Castanaza, the largest self-reported group is Hispanic at 97.5%. The next largest groups are White (2.5%). 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?
Hispanic is the largest self-reported group for the surname Castanaza in the 2020 Census, accounting for 97.5% (116 people in the source table).
What is the full ancestry breakdown?
Castanaza appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are Hispanic (97.5%), White (2.5%). 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 Castanaza (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 Castanaza mean?
A surname originating from Spain, derived from the Spanish word "castaña" meaning chestnut. 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 Castanaza (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 people share the surname Castanaza?
HowManyOfMe.org, our sister site, answers that with the living-bearer count in one glance.