2000
#11,758
National surname rank
Recorded bearers 2,441
First available Census row
Per 100,000 0.90
Rare Last name
Lou
A Chinese surname derived from the name of an ancient state or a reference to a pavilion or tower.
According to the 2020 US Census Bureau surname tables, roughly 4,150 Americans carry the last name Lou. That puts it at #8,700 in the national surname ranking, appearing at a frequency of 1.21 per 100,000 people (about 1 in 82,591 residents).
This page is the full Name Census profile for the Lou 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.
For British records, Name Census UK has a British surname profile for Lou with 1881 census detail, origin facts and modern UK distribution where available.
Bearers in the US
4.2K
1 in 82,591
Census rank
#8,700
2020 decennial data
Per 100,000
1.2
Frequency rate
Recorded bearers
3.6K
rare in the US
Popularity narrative
The Census Bureau recorded 3,619 bearers of the surname Lou in its 2020 decennial surname file. At a rate of 1.21 per 100,000 residents, it holds the 8700th position in the national surname ranking.
Among Census respondents with the surname Lou, the largest self-reported group is Asian/Pacific Islander at 79.6%. The next largest groups are White (10.9%) and Two or More Races (3.4%).
Origin
Meaning and origin of Lou
The surname Lou has its origins in China, where it is believed to have first emerged during the Tang Dynasty (618-907 AD). The name is derived from the Chinese word "lou," which means "building" or "structure." It is thought that the surname may have been given to families involved in construction or architecture.
One of the earliest recorded instances of the Lou surname can be found in the "Jiu Tang Shu," a historical text from the 10th century AD. This book mentions several individuals with the Lou surname, including a government official named Lou Zhi who served during the reign of Emperor Xuanzong in the 8th century.
During the Song Dynasty (960-1279 AD), the Lou surname became more widespread, particularly in the regions of Zhejiang and Jiangsu. Several prominent individuals from this period bore the Lou surname, including the renowned philosopher and writer Lou Yue (1137-1213), who is known for his influential work "Gengzhitu."
In the Ming Dynasty (1368-1644), the Lou surname was associated with several notable figures, such as the painter Lou Qingxi (1550-1619), who was renowned for his landscape paintings and calligraphic works. Another important figure from this period was Lou Liang (1422-1491), a scholar and official who served as a minister during the Chenghua Emperor's reign.
During the Qing Dynasty (1644-1912), the Lou surname continued to be prominent, with individuals like Lou Guanzhong (1330-1400), the author of the classic novel "Romance of the Three Kingdoms," and Lou Jingxi (1593-1671), a respected scholar and poet.
Other notable individuals with the Lou surname throughout history include Lou Zhuangyuan (1455-1533), a renowned scholar and educator during the Ming Dynasty, and Lou Wenhuan (1718-1794), a prominent painter and calligrapher of the Qing Dynasty.
It is worth noting that while the Lou surname is most commonly associated with China, it has also been found in other parts of Asia, such as Korea and Vietnam, likely due to migration and cultural exchange over the centuries.
Demographics
Ancestry and ethnicity for Lou
Among Census respondents with the surname Lou, the largest self-reported group is Asian/Pacific Islander at 79.6%. The next largest groups are White (10.9%) and Two or More Races (3.4%).
The bar chart below shows how Lou 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 Lou surname at the time of the 2020 Census, not any inherent property of the name itself.
- Asian and Pacific Islander79.6% · 2,882
- White10.9% · 396
- Two or more races3.4% · 124
- Hispanic or Latino3.2% · 114
- Black or African American2.7% · 99
- American Indian and Alaska Native0.1% · 4
Timeline
Historical Census data for Lou
Lou 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
#10,815
National surname rank
Recorded bearers 2,945
+504 bearers (+20.6%)
Per 100,000 1.00
Rank movement Up 943 places
2020
#8,700
National surname rank
Recorded bearers 3,619
+674 bearers (+22.9%)
Per 100,000 1.21
Rank movement Up 2,115 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2000 | #11,758 | 2,441 | 0.90 | First available Census row | First available Census row |
| 2010 | #10,815 | 2,945 | 1.00 | +504 bearers (+20.6%) | Up 943 places |
| 2020 | #8,700 | 3,619 | 1.21 | +674 bearers (+22.9%) | Up 2,115 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 Lou 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 | #10,815 | #8,700 | 19.6% |
| Count | 2,945 | 3,619 | 22.9% |
| Per 100K | 1.00 | 1.21 | 21.1% |
Between the 2010 and 2020 Census, the number of Lou bearers went from 2,945 to 3,619 (+22.9% change). The surname moved up 2,115 positions in the national ranking, going from #10,815 to #8,700.
FAQ
Lou surname: questions and answers
How many people in the U.S. have the surname Lou?
Name Census estimates that about 4,150 living Americans carry the surname Lou. Using the current population baseline, that works out to roughly 1 in 82,591 residents.
How common is Lou?
Lou ranks #8,700 in the 2020 Census surname tables and is classified on this site as "Rare." The Census recorded the name at a frequency of 1.21 per 100,000 residents, which is about 1 people out of every 100,000.
How many people with this surname were counted in the Census?
The raw 2020 Census file counted 3,619 people with the surname Lou. That is different from the site's living-bearer estimate (4,150), which projects the surname's present-day count by applying the Census frequency rate to the current U.S. population.
What does 1.21 per 100,000 actually mean?
It is the Census Bureau's normalized frequency measure. A rate of 1.21 per 100,000 means that if you picked a random group of 100,000 U.S. residents, you would expect about 1 of them to have the surname Lou.
Has Lou become more or less common over time?
Between 2010 and 2020, the surname Lou went from 2,945 recorded bearers to 3,619. That is an increase of 674 (+22.9%). In the national ranking it rose from #10,815 to #8,700.
What does the Census say about the background of Lou?
Among Census respondents with the surname Lou, the largest self-reported group is Asian/Pacific Islander at 79.6%. The next largest groups are White (10.9%) and Two or More Races (3.4%). 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 Lou in the 2020 Census, accounting for 79.6% (2,882 people in the source table).
What is the full ancestry breakdown?
Lou appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are Asian/Pacific Islander (79.6%), White (10.9%), Two or More Races (3.4%). 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 Lou (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 Lou mean?
A Chinese surname derived from the name of an ancient state or a reference to a pavilion or tower. 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 Lou (1.21 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 Lou?
For a faster, more casual read, check HowManyOfMe.org — our sister site built around that single question.