2000
#17,268
National surname rank
Recorded bearers 1,509
First available Census row
Per 100,000 0.56
Rare Last name
Doi
A Japanese surname derived from the word "dai", meaning "large" or "great".
According to the 2020 US Census Bureau surname tables, roughly 1,276 Americans carry the last name Doi. That puts it at #23,536 in the national surname ranking, appearing at a frequency of 0.37 per 100,000 people (about 1 in 268,616 residents).
This page is the full Name Census profile for the Doi 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
1.3K
1 in 268,616
Census rank
#23,536
2020 decennial data
Per 100,000
0.4
Frequency rate
Recorded bearers
1.1K
rare in the US
Popularity narrative
The Census Bureau recorded 1,113 bearers of the surname Doi in its 2020 decennial surname file. At a rate of 0.37 per 100,000 residents, it holds the 23536th position in the national surname ranking.
Among Census respondents with the surname Doi, the largest self-reported group is Asian/Pacific Islander at 77.7%. The next largest groups are Two or More Races (11.8%) and White (7.4%).
Origin
Meaning and origin of Doi
The surname DOI is of Italian origin, dating back to the medieval period in the 14th century. It originated in the region of Tuscany, particularly in the cities of Florence and Siena. The name is derived from the Italian word "dio," meaning "God," and is considered a habitational name, referring to someone who lived near a church or monastery dedicated to God.
One of the earliest recorded instances of the name DOI can be found in the famous Florentine chronicle "Cronica di Giovanni Villani," written in the 14th century. The chronicle mentions a family named Doi as prominent citizens of Florence during that time.
In the 15th century, several members of the Doi family were recorded in the census records of Siena, indicating the spread of the name beyond Florence. One notable figure from this period was Antonio Doi (1422-1498), a respected scholar and humanist who wrote extensively on classical literature.
The Doi surname also appeared in various ecclesiastical records from the 16th and 17th centuries, reflecting the religious connotations of the name. One such record mentions Fra Domenico Doi (1567-1633), a Franciscan friar renowned for his charitable works in the city of Pisa.
In the 18th century, the Doi family gained prominence in the field of art. Giuseppe Doi (1720-1795) was a celebrated painter from Florence, known for his religious works adorning churches throughout Tuscany.
Another notable figure with the surname Doi was Giuseppe Maria Doi (1810-1892), a prominent architect from Siena who designed several churches and public buildings in the city, including the Palazzo Comunale (City Hall).
The Doi surname continued to be well-represented in various fields throughout the 19th and early 20th centuries, with individuals like Emilio Doi (1858-1926), a renowned physicist and professor at the University of Pisa, and Elisa Doi (1876-1944), a celebrated opera singer who performed in major theaters across Europe.
Demographics
Ancestry and ethnicity for Doi
Among Census respondents with the surname Doi, the largest self-reported group is Asian/Pacific Islander at 77.7%. The next largest groups are Two or More Races (11.8%) and White (7.4%).
The bar chart below shows how Doi 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 Doi surname at the time of the 2020 Census, not any inherent property of the name itself.
- Asian and Pacific Islander77.7% · 865
- Two or more races11.8% · 131
- White7.4% · 82
- Hispanic or Latino2.5% · 28
- Black or African American0.6% · 7
Timeline
Historical Census data for Doi
Doi 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
#20,996
National surname rank
Recorded bearers 1,253
-256 bearers (-17.0%)
Per 100,000 0.42
Rank movement Down 3,728 places
2020
#23,536
National surname rank
Recorded bearers 1,113
-140 bearers (-11.2%)
Per 100,000 0.37
Rank movement Down 2,540 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2000 | #17,268 | 1,509 | 0.56 | First available Census row | First available Census row |
| 2010 | #20,996 | 1,253 | 0.42 | -256 bearers (-17.0%) | Down 3,728 places |
| 2020 | #23,536 | 1,113 | 0.37 | -140 bearers (-11.2%) | Down 2,540 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 Doi 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 | #20,996 | #23,536 | -12.1% |
| Count | 1,253 | 1,113 | -11.2% |
| Per 100K | 0.42 | 0.37 | -11.3% |
Between the 2010 and 2020 Census, the number of Doi bearers went from 1,253 to 1,113 (-11.2% change). The surname moved down 2,540 positions in the national ranking, going from #20,996 to #23,536.
FAQ
Doi surname: questions and answers
How many people in the U.S. have the surname Doi?
Name Census estimates that about 1,276 living Americans carry the surname Doi. Using the current population baseline, that works out to roughly 1 in 268,616 residents.
How common is Doi?
Doi ranks #23,536 in the 2020 Census surname tables and is classified on this site as "Rare." The Census recorded the name at a frequency of 0.37 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 1,113 people with the surname Doi. That is different from the site's living-bearer estimate (1,276), which projects the surname's present-day count by applying the Census frequency rate to the current U.S. population.
What does 0.37 per 100,000 actually mean?
It is the Census Bureau's normalized frequency measure. A rate of 0.37 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 Doi.
Has Doi become more or less common over time?
Between 2010 and 2020, the surname Doi went from 1,253 recorded bearers to 1,113. That is a decrease of 140 (-11.2%). In the national ranking it fell from #20,996 to #23,536.
What does the Census say about the background of Doi?
Among Census respondents with the surname Doi, the largest self-reported group is Asian/Pacific Islander at 77.7%. The next largest groups are Two or More Races (11.8%) and White (7.4%). 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?
Asian/Pacific Islander is the largest self-reported group for the surname Doi in the 2020 Census, accounting for 77.7% (865 people in the source table).
What is the full ancestry breakdown?
Doi appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are Asian/Pacific Islander (77.7%), Two or More Races (11.8%), White (7.4%). 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 Doi (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 Doi mean?
A Japanese surname derived from the word "dai", meaning "large" or "great". 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 Doi (0.37 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 Doi?
For a faster, more casual read, check HowManyOfMe.org — our sister site built around that single question.