2000
#132,259
National surname rank
Recorded bearers 118
First available Census row
Per 100,000 0.04
Very Rare Last name
Rat
A surname derived from the French word for a rodent, possibly a nickname or description.
According to the 2020 US Census Bureau surname tables, roughly 119 Americans carry the last name Rat. That puts it at #153,590 in the national surname ranking, appearing at a frequency of 0.03 per 100,000 people (about 1 in 2,880,289 residents).
This page is the full Name Census profile for the Rat 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
119
1 in 2,880,289
Census rank
#153,590
2020 decennial data
Per 100,000
0.0
Frequency rate
Recorded bearers
104
very rare in the US
Popularity narrative
The Census Bureau recorded 104 bearers of the surname Rat in its 2020 decennial surname file. At a rate of 0.03 per 100,000 residents, it holds the 153590th position in the national surname ranking.
Among Census respondents with the surname Rat, the largest self-reported group is White at 65.4%. The next largest groups are Asian/Pacific Islander (14.4%) and Black (11.5%).
Origin
Meaning and origin of Rat
The surname Rat is believed to have originated in Germany during the Middle Ages. It is thought to be derived from the Old German word "ratte," which means "rat." The name may have initially been a nickname or descriptive name given to someone who resembled or had a close association with rats.
In medieval times, surnames often arose from occupations, physical characteristics, or locations. The name Rat could have been given to someone who worked as a rat catcher or exterminator, or it might have referred to a person's physical appearance or behavior that was likened to a rat.
One of the earliest recorded instances of the surname Rat can be found in the Codex Diplomaticus, a collection of medieval German documents from the 13th century. The name appears in this codex as early as 1275, with a reference to a man named Henricus dictus Rat (Henry called Rat).
Another early recorded example of the name is found in the Nuremberg Chronicles, a 16th-century illustrated world history book published in 1493. The book mentions a German knight named Rudolph Rat, who lived in the late 14th century.
During the Renaissance period, the surname Rat can be found in various records and manuscripts across Germany and neighboring regions. One notable figure was Johannes Rat, a German mathematician and astronomer born in 1498 in Erfurt, who made significant contributions to the study of trigonometry and authored several works on mathematics.
In the 17th century, the name appears in the records of the University of Heidelberg, with a reference to a student named Georg Rat, who enrolled in 1621.
Another noteworthy individual with the surname Rat was Johann Rat, a German composer and organist who lived from 1685 to 1756. He is known for his contributions to the development of the German Baroque music style.
As the surname Rat spread across Europe, it often took on variations in spelling and pronunciation based on regional dialects and languages. For instance, in France, the name was sometimes spelled as "Ratz" or "Ratte," while in English-speaking regions, it could be found as "Ratt" or "Ratte."
Over the centuries, the surname Rat has been associated with various place names and locations, such as Ratheim in Germany, Ratingen in North Rhine-Westphalia, and Ratlangen in Lower Saxony, among others. These place names may have influenced the spread and variations of the surname in different regions.
Demographics
Ancestry and ethnicity for Rat
Among Census respondents with the surname Rat, the largest self-reported group is White at 65.4%. The next largest groups are Asian/Pacific Islander (14.4%) and Black (11.5%).
The bar chart below shows how Rat 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 Rat surname at the time of the 2020 Census, not any inherent property of the name itself.
- White65.4% · 68
- Asian and Pacific Islander14.4% · 15
- Black or African American11.5% · 12
- Hispanic or Latino5.8% · 6
- Two or more races1.9% · 2
- American Indian and Alaska Native1.0% · 1
Timeline
Historical Census data for Rat
Rat 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
#146,201
National surname rank
Recorded bearers 113
-5 bearers (-4.2%)
Per 100,000 0.04
Rank movement Down 13,942 places
2020
#153,590
National surname rank
Recorded bearers 104
-9 bearers (-8.0%)
Per 100,000 0.03
Rank movement Down 7,389 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2000 | #132,259 | 118 | 0.04 | First available Census row | First available Census row |
| 2010 | #146,201 | 113 | 0.04 | -5 bearers (-4.2%) | Down 13,942 places |
| 2020 | #153,590 | 104 | 0.03 | -9 bearers (-8.0%) | Down 7,389 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 Rat 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 | #146,201 | #153,590 | -5.1% |
| Count | 113 | 104 | -8.0% |
| Per 100K | 0.04 | 0.03 | -13.0% |
Between the 2010 and 2020 Census, the number of Rat bearers went from 113 to 104 (-8.0% change). The surname moved down 7,389 positions in the national ranking, going from #146,201 to #153,590.
FAQ
Rat surname: questions and answers
How many people in the U.S. have the surname Rat?
Name Census estimates that about 119 living Americans carry the surname Rat. Using the current population baseline, that works out to roughly 1 in 2,880,289 residents.
How common is Rat?
Rat ranks #153,590 in the 2020 Census surname tables and is classified on this site as "Very Rare." The Census recorded the name at a frequency of 0.03 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 104 people with the surname Rat. That is different from the site's living-bearer estimate (119), which projects the surname's present-day count by applying the Census frequency rate to the current U.S. population.
What does 0.03 per 100,000 actually mean?
It is the Census Bureau's normalized frequency measure. A rate of 0.03 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 Rat.
Has Rat become more or less common over time?
Between 2010 and 2020, the surname Rat went from 113 recorded bearers to 104. That is a decrease of 9 (-8.0%). In the national ranking it fell from #146,201 to #153,590.
What does the Census say about the background of Rat?
Among Census respondents with the surname Rat, the largest self-reported group is White at 65.4%. The next largest groups are Asian/Pacific Islander (14.4%) and Black (11.5%). 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 Rat in the 2020 Census, accounting for 65.4% (68 people in the source table).
What is the full ancestry breakdown?
Rat appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are White (65.4%), Asian/Pacific Islander (14.4%), Black (11.5%). 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 Rat (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 Rat mean?
A surname derived from the French word for a rodent, possibly a nickname or description. 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 Rat (0.03 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 Rat?
If you just want to know how many people have the surname Rat, HowManyOfMe.org gives you the headline number in one glance.