2010
#147,253
National surname rank
Recorded bearers 112
First available Census row
Per 100,000 0.04
Very Rare Last name
Decotiis
A surname derived from an Italian occupational name referring to a maker or seller of quilts or comforters.
According to the 2020 US Census Bureau surname tables, roughly 124 Americans carry the last name Decotiis. That puts it at #150,935 in the national surname ranking, appearing at a frequency of 0.04 per 100,000 people (about 1 in 2,764,148 residents).
This page is the full Name Census profile for the Decotiis 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
124
1 in 2,764,148
Census rank
#150,935
2020 decennial data
Per 100,000
0.0
Frequency rate
Recorded bearers
108
very rare in the US
Popularity narrative
The Census Bureau recorded 108 bearers of the surname Decotiis in its 2020 decennial surname file. At a rate of 0.04 per 100,000 residents, it holds the 150935th position in the national surname ranking.
Among Census respondents with the surname Decotiis, the largest self-reported group is White at 92.6%. The next largest groups are Hispanic (4.6%) and Two or More Races (2.8%).
Origin
Meaning and origin of Decotiis
The surname DECOTIIS originates from Italy, specifically the northern regions of Lombardy and Veneto. It is believed to have emerged during the latter part of the Middle Ages, around the 13th or 14th century.
DECOTIIS is thought to be a locational surname, derived from a place name or geographical feature. One theory suggests that it may have originated from the Latin phrase "de cotiis," meaning "of the hills" or "from the hills," which could indicate that the earliest bearers of this surname hailed from a hilly or mountainous region.
Another possible origin is that DECOTIIS is a variant spelling of the Italian surname "De Cottis," which is believed to be derived from the ancient Roman name "Cottius." Cottius was a ruler of a small Celtic kingdom in the western Alps region during the 1st century BC, and his name may have been adopted as a surname by those living in the areas he governed.
Early records mentioning the surname DECOTIIS are scarce, but some documents from the 15th and 16th centuries in northern Italy reference individuals with this name. One notable example is a manuscript from the city of Verona, dated 1487, which mentions a merchant named Giovanni DECOTIIS.
In the 17th century, a prominent figure with the surname DECOTIIS was Girolamo DECOTIIS (1597-1667), a Venetian writer and philosopher who authored several works on logic and metaphysics. Another notable individual was Antonio DECOTIIS (1679-1743), a lawyer and jurist from Milan who served as a magistrate and legal advisor to the Duchy of Milan.
During the 18th century, the DECOTIIS surname continued to be found in various parts of northern Italy, particularly in the regions of Lombardy, Veneto, and Piedmont. One noteworthy figure from this period was Giuseppe DECOTIIS (1725-1793), a prominent architect from Bergamo who designed several churches and public buildings in his native city.
In the 19th century, the name DECOTIIS was carried by individuals such as Emilio DECOTIIS (1812-1887), a poet and writer from Verona, and Alessandro DECOTIIS (1842-1917), a businessman and philanthropist from Milan who founded a charitable organization to support underprivileged children.
While the surname DECOTIIS is not among the most common Italian surnames, it has a rich history spanning several centuries and is deeply rooted in the northern regions of Italy, particularly in the areas around Milan, Verona, and Venice.
Demographics
Ancestry and ethnicity for Decotiis
Among Census respondents with the surname Decotiis, the largest self-reported group is White at 92.6%. The next largest groups are Hispanic (4.6%) and Two or More Races (2.8%).
The bar chart below shows how Decotiis 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 Decotiis surname at the time of the 2020 Census, not any inherent property of the name itself.
- White92.6% · 100
- Hispanic or Latino4.6% · 5
- Two or more races2.8% · 3
Timeline
Historical Census data for Decotiis
Decotiis 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
#150,935
National surname rank
Recorded bearers 108
-4 bearers (-3.6%)
Per 100,000 0.04
Rank movement Down 3,682 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2010 | #147,253 | 112 | 0.04 | First available Census row | First available Census row |
| 2020 | #150,935 | 108 | 0.04 | -4 bearers (-3.6%) | Down 3,682 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 Decotiis 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 | #147,253 | #150,935 | -2.5% |
| Count | 112 | 108 | -3.6% |
| Per 100K | 0.04 | 0.04 | -9.7% |
Between the 2010 and 2020 Census, the number of Decotiis bearers went from 112 to 108 (-3.6% change). The surname moved down 3,682 positions in the national ranking, going from #147,253 to #150,935.
FAQ
Decotiis surname: questions and answers
How many people in the U.S. have the surname Decotiis?
Name Census estimates that about 124 living Americans carry the surname Decotiis. Using the current population baseline, that works out to roughly 1 in 2,764,148 residents.
How common is Decotiis?
Decotiis ranks #150,935 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 108 people with the surname Decotiis. That is different from the site's living-bearer estimate (124), 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 Decotiis.
Has Decotiis become more or less common over time?
Between 2010 and 2020, the surname Decotiis went from 112 recorded bearers to 108. That is a decrease of 4 (-3.6%). In the national ranking it fell from #147,253 to #150,935.
What does the Census say about the background of Decotiis?
Among Census respondents with the surname Decotiis, the largest self-reported group is White at 92.6%. The next largest groups are Hispanic (4.6%) and Two or More Races (2.8%). 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 Decotiis in the 2020 Census, accounting for 92.6% (100 people in the source table).
What is the full ancestry breakdown?
Decotiis appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are White (92.6%), Hispanic (4.6%), Two or More Races (2.8%). 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 Decotiis (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 Decotiis mean?
A surname derived from an Italian occupational name referring to a maker or seller of quilts or comforters. 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 Decotiis (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 Decotiis?
For a faster, more casual read, check HowManyOfMe.org — our sister site built around that single question.