2000
#130,443
National surname rank
Recorded bearers 120
First available Census row
Per 100,000 0.04
Very Rare Last name
Costolo
A surname derived from the Italian word "costolo," meaning "rib" or "side."
According to the 2020 US Census Bureau surname tables, roughly 135 Americans carry the last name Costolo. That puts it at #143,511 in the national surname ranking, appearing at a frequency of 0.04 per 100,000 people (about 1 in 2,538,921 residents).
This page is the full Name Census profile for the Costolo 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
135
1 in 2,538,921
Census rank
#143,511
2020 decennial data
Per 100,000
0.0
Frequency rate
Recorded bearers
118
very rare in the US
Popularity narrative
The Census Bureau recorded 118 bearers of the surname Costolo in its 2020 decennial surname file. At a rate of 0.04 per 100,000 residents, it holds the 143511th position in the national surname ranking.
Among Census respondents with the surname Costolo, the largest self-reported group is White at 91.5%. The next largest groups are Hispanic (4.2%) and Two or More Races (2.5%).
Origin
Meaning and origin of Costolo
The surname Costolo originated in Italy, likely during the Middle Ages. It is believed to have derived from the Italian word "costola," which means "rib" or "side." The name may have initially referred to someone who lived near a prominent hill or ridge, or it could have been a nickname for a person with a distinctive physical characteristic related to their ribs or sides.
One of the earliest recorded instances of the name Costolo can be found in a document from the city of Siena, dated 1389. This document mentions a certain Giulio Costolo, who was a merchant in the city at that time. Another early record comes from the town of Lucca, where a family named Costolo is mentioned in a document from the late 15th century.
During the Renaissance period, several notable individuals bore the surname Costolo. In the 16th century, there was a famous painter named Lorenzo Costolo (1460-1535), who was known for his religious works and frescoes in churches throughout Tuscany. Another notable figure was Giacomo Costolo (1520-1598), a scholar and philosopher who taught at the University of Bologna.
The name Costolo also appears in some historical records related to the Italian unification movement in the 19th century. One such figure was Carlo Costolo (1815-1888), a patriot and soldier who fought alongside Giuseppe Garibaldi in the campaign to unify Italy under the House of Savoy.
In the 20th century, one of the most prominent individuals with the surname Costolo was Aldo Costolo (1912-1998), an Italian-American businessman and philanthropist. Born in Sicily, he immigrated to the United States and founded a successful construction company in New York City. He was also known for his charitable contributions to various educational and cultural institutions.
Another notable figure was Vincenzo Costolo (1928-2011), an Italian writer and journalist who worked for several prominent newspapers and magazines in Italy. He was particularly known for his coverage of political and social issues during the turbulent years of the post-war period.
While the surname Costolo is not among the most common Italian surnames, it has a rich history spanning several centuries and has been associated with individuals from various walks of life, including artists, scholars, patriots, and entrepreneurs.
Demographics
Ancestry and ethnicity for Costolo
Among Census respondents with the surname Costolo, the largest self-reported group is White at 91.5%. The next largest groups are Hispanic (4.2%) and Two or More Races (2.5%).
The bar chart below shows how Costolo 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 Costolo surname at the time of the 2020 Census, not any inherent property of the name itself.
- White91.5% · 108
- Hispanic or Latino4.2% · 5
- Two or more races2.5% · 3
- Black or African American0.8% · 1
- Asian and Pacific Islander0.8% · 1
Timeline
Historical Census data for Costolo
Costolo 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
#138,304
National surname rank
Recorded bearers 121
+1 bearers (+0.8%)
Per 100,000 0.04
Rank movement Down 7,861 places
2020
#143,511
National surname rank
Recorded bearers 118
-3 bearers (-2.5%)
Per 100,000 0.04
Rank movement Down 5,207 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2000 | #130,443 | 120 | 0.04 | First available Census row | First available Census row |
| 2010 | #138,304 | 121 | 0.04 | +1 bearers (+0.8%) | Down 7,861 places |
| 2020 | #143,511 | 118 | 0.04 | -3 bearers (-2.5%) | Down 5,207 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 Costolo 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 | #138,304 | #143,511 | -3.8% |
| Count | 121 | 118 | -2.5% |
| Per 100K | 0.04 | 0.04 | -1.3% |
Between the 2010 and 2020 Census, the number of Costolo bearers went from 121 to 118 (-2.5% change). The surname moved down 5,207 positions in the national ranking, going from #138,304 to #143,511.
FAQ
Costolo surname: questions and answers
How many people in the U.S. have the surname Costolo?
Name Census estimates that about 135 living Americans carry the surname Costolo. Using the current population baseline, that works out to roughly 1 in 2,538,921 residents.
How common is Costolo?
Costolo ranks #143,511 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 118 people with the surname Costolo. That is different from the site's living-bearer estimate (135), 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 Costolo.
Has Costolo become more or less common over time?
Between 2010 and 2020, the surname Costolo went from 121 recorded bearers to 118. That is a decrease of 3 (-2.5%). In the national ranking it fell from #138,304 to #143,511.
What does the Census say about the background of Costolo?
Among Census respondents with the surname Costolo, the largest self-reported group is White at 91.5%. The next largest groups are Hispanic (4.2%) and Two or More Races (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?
White is the largest self-reported group for the surname Costolo in the 2020 Census, accounting for 91.5% (108 people in the source table).
What is the full ancestry breakdown?
Costolo appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are White (91.5%), Hispanic (4.2%), Two or More Races (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 Costolo (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 Costolo mean?
A surname derived from the Italian word "costolo," meaning "rib" or "side." 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 Costolo (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 common is the surname Costolo?
Our sister site HowManyOfMe.org answers how many people have the last name Costolo at a glance, with the living-bearer count up front.