2010
#151,532
National surname rank
Recorded bearers 108
First available Census row
Per 100,000 0.04
Very Rare Last name
Erario
An uncommon Italian surname possibly derived from the word "erario," meaning "treasury."
According to the 2020 US Census Bureau surname tables, roughly 120 Americans carry the last name Erario. That puts it at #152,989 in the national surname ranking, appearing at a frequency of 0.04 per 100,000 people (about 1 in 2,856,286 residents).
This page is the full Name Census profile for the Erario 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
120
1 in 2,856,286
Census rank
#152,989
2020 decennial data
Per 100,000
0.0
Frequency rate
Recorded bearers
105
very rare in the US
Popularity narrative
The Census Bureau recorded 105 bearers of the surname Erario in its 2020 decennial surname file. At a rate of 0.04 per 100,000 residents, it holds the 152989th position in the national surname ranking.
Among Census respondents with the surname Erario, the largest self-reported group is White at 89.5%. The next largest groups are Hispanic (6.7%) and Two or More Races (2.9%).
Origin
Meaning and origin of Erario
The surname Erario is of Italian origin and can be traced back to the late medieval period, around the 13th or 14th century. It is believed to have originated in the regions of Lombardy and Piedmont, where it was initially spelled as "Erario" or "Erari".
The name Erario is derived from the Latin word "aerarium", which referred to the public treasury or the state's financial department in ancient Rome. This connection suggests that the earliest bearers of this surname may have held positions related to finance, taxation, or the management of public funds.
One of the earliest recorded instances of the Erario name can be found in a document from the city of Milan, dated 1289, which mentions a certain "Guidone Erario". This suggests that the name was already established in the Lombardy region by the late 13th century.
In the 15th century, the Erario family gained prominence in the city of Alessandria, located in the Piedmont region. Several members of this family held important positions in the local government and church. One notable figure was Giovanni Battista Erario (1430-1498), who served as the Bishop of Alessandria from 1478 until his death.
Another prominent individual with the Erario surname was Sebastiano Erario (1510-1585), a Renaissance humanist and writer from Milan. He was a prolific author and is best known for his work "De rebus Mediolanensibus" (On the Affairs of Milan), a historical account of the city's events during his lifetime.
In the 17th century, the Erario family had a presence in the town of Casale Monferrato, also located in Piedmont. Records from this period mention a certain Girolamo Erario (1620-1698), who served as a magistrate and held various administrative positions in the local government.
Moving forward to the 18th century, we find Francesco Erario (1728-1802), a renowned Italian jurist and legal scholar from Naples. He was a professor of law at the University of Naples and authored several influential works on civil and commercial law.
Throughout its history, the Erario surname has been associated with various place names and locations, such as Erario di Castellamonte (a town in Piedmont), Erario di Casale Monferrato (a district in Casale Monferrato), and Erario di Milano (a neighborhood in Milan). These place names likely derived from the presence of Erario families in those areas.
Demographics
Ancestry and ethnicity for Erario
Among Census respondents with the surname Erario, the largest self-reported group is White at 89.5%. The next largest groups are Hispanic (6.7%) and Two or More Races (2.9%).
The bar chart below shows how Erario 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 Erario surname at the time of the 2020 Census, not any inherent property of the name itself.
- White89.5% · 94
- Hispanic or Latino6.7% · 7
- Two or more races2.9% · 3
- Asian and Pacific Islander1.0% · 1
Timeline
Historical Census data for Erario
Erario 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
#152,989
National surname rank
Recorded bearers 105
-3 bearers (-2.8%)
Per 100,000 0.04
Rank movement Down 1,457 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2010 | #151,532 | 108 | 0.04 | First available Census row | First available Census row |
| 2020 | #152,989 | 105 | 0.04 | -3 bearers (-2.8%) | Down 1,457 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 Erario 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 | #151,532 | #152,989 | -1.0% |
| Count | 108 | 105 | -2.8% |
| Per 100K | 0.04 | 0.04 | -12.2% |
Between the 2010 and 2020 Census, the number of Erario bearers went from 108 to 105 (-2.8% change). The surname moved down 1,457 positions in the national ranking, going from #151,532 to #152,989.
FAQ
Erario surname: questions and answers
How many people in the U.S. have the surname Erario?
Name Census estimates that about 120 living Americans carry the surname Erario. Using the current population baseline, that works out to roughly 1 in 2,856,286 residents.
How common is Erario?
Erario ranks #152,989 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 105 people with the surname Erario. That is different from the site's living-bearer estimate (120), 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 Erario.
Has Erario become more or less common over time?
Between 2010 and 2020, the surname Erario went from 108 recorded bearers to 105. That is a decrease of 3 (-2.8%). In the national ranking it fell from #151,532 to #152,989.
What does the Census say about the background of Erario?
Among Census respondents with the surname Erario, the largest self-reported group is White at 89.5%. The next largest groups are Hispanic (6.7%) and Two or More Races (2.9%). 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 Erario in the 2020 Census, accounting for 89.5% (94 people in the source table).
What is the full ancestry breakdown?
Erario appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are White (89.5%), Hispanic (6.7%), Two or More Races (2.9%). 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 Erario (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 Erario mean?
An uncommon Italian surname possibly derived from the word "erario," meaning "treasury." 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 Erario (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 Erario?
For a quick modern estimate, our sister site HowManyOfMe.org answers that in one glance, with the living-bearer count front and centre.