2000
#88,461
National surname rank
Recorded bearers 195
First available Census row
Per 100,000 0.07
Very Rare Last name
Mastny
A surname likely derived from the Czech word "mastný" meaning greasy or oily.
According to the 2020 US Census Bureau surname tables, roughly 255 Americans carry the last name Mastny. That puts it at #89,563 in the national surname ranking, appearing at a frequency of 0.07 per 100,000 people (about 1 in 1,344,135 residents).
This page is the full Name Census profile for the Mastny 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
255
1 in 1,344,135
Census rank
#89,563
2020 decennial data
Per 100,000
0.1
Frequency rate
Recorded bearers
222
very rare in the US
Popularity narrative
The Census Bureau recorded 222 bearers of the surname Mastny in its 2020 decennial surname file. At a rate of 0.07 per 100,000 residents, it holds the 89563rd position in the national surname ranking.
Among Census respondents with the surname Mastny, the largest self-reported group is White at 90.1%. The next largest groups are Hispanic (4.1%) and Two or More Races (4.1%).
Origin
Meaning and origin of Mastny
The surname Mastny originates from the Czech Republic, tracing its roots back to the late 15th century. It is derived from the Czech word "mastny," which means "oily" or "greasy." This suggests that the name may have been an occupational surname given to individuals involved in professions related to oils or fats, such as candle makers, soap makers, or workers in tanneries.
The earliest recorded instances of the name Mastny can be found in historical records from the regions of Bohemia and Moravia, which were parts of the Kingdom of Bohemia during the medieval period. One of the earliest documented references to the name is in a register of inhabitants from the town of Kutná Hora, dated 1487.
In the 16th and 17th centuries, variations of the spelling, such as "Mastny," "Mastnyi," and "Mastnij," appeared in various records and manuscripts from the Czech lands. These variations likely emerged due to regional dialects and the absence of standardized spelling conventions at the time.
One notable individual bearing the surname Mastny was Jan Mastny, a prominent Czech painter and engraver born in 1543 in the town of Broumov. His artwork, particularly his religious engravings, adorned numerous churches and monasteries throughout Bohemia during the late Renaissance period.
In the 18th century, the name Mastny gained prominence in the region of Silesia, which was then part of the Austrian Empire. Anna Mastny, born in 1712 in the town of Opava, was a renowned herbalist and healer whose expertise in traditional remedies was widely sought after by the local populace.
During the 19th century, the surname Mastny spread beyond the borders of the Czech lands as some families immigrated to other parts of Europe and North America. One notable figure was Jakub Mastny, a Czech-American entrepreneur who founded the Mastny Brewing Company in Chicago in 1876, contributing to the city's rich brewing heritage.
Other prominent individuals with the surname Mastny include Josef Mastny, a Czech painter and illustrator born in 1867, whose works depicted scenes from rural life in Bohemia. Additionally, Vojtěch Mastny, born in 1936, was a prominent Czech historian and political scientist who specialized in Cold War studies and served as a professor at various universities in the United States and Europe.
Demographics
Ancestry and ethnicity for Mastny
Among Census respondents with the surname Mastny, the largest self-reported group is White at 90.1%. The next largest groups are Hispanic (4.1%) and Two or More Races (4.1%).
The bar chart below shows how Mastny 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 Mastny surname at the time of the 2020 Census, not any inherent property of the name itself.
- White90.1% · 200
- Hispanic or Latino4.1% · 9
- Two or more races4.1% · 9
- Asian and Pacific Islander1.4% · 3
- American Indian and Alaska Native0.5% · 1
Timeline
Historical Census data for Mastny
Mastny 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
#83,834
National surname rank
Recorded bearers 224
+29 bearers (+14.9%)
Per 100,000 0.08
Rank movement Up 4,627 places
2020
#89,563
National surname rank
Recorded bearers 222
-2 bearers (-0.9%)
Per 100,000 0.07
Rank movement Down 5,729 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2000 | #88,461 | 195 | 0.07 | First available Census row | First available Census row |
| 2010 | #83,834 | 224 | 0.08 | +29 bearers (+14.9%) | Up 4,627 places |
| 2020 | #89,563 | 222 | 0.07 | -2 bearers (-0.9%) | Down 5,729 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 Mastny 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 | #83,834 | #89,563 | -6.8% |
| Count | 224 | 222 | -0.9% |
| Per 100K | 0.08 | 0.07 | -7.2% |
Between the 2010 and 2020 Census, the number of Mastny bearers went from 224 to 222 (-0.9% change). The surname moved down 5,729 positions in the national ranking, going from #83,834 to #89,563.
FAQ
Mastny surname: questions and answers
How many people in the U.S. have the surname Mastny?
Name Census estimates that about 255 living Americans carry the surname Mastny. Using the current population baseline, that works out to roughly 1 in 1,344,135 residents.
How common is Mastny?
Mastny ranks #89,563 in the 2020 Census surname tables and is classified on this site as "Very Rare." The Census recorded the name at a frequency of 0.07 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 222 people with the surname Mastny. That is different from the site's living-bearer estimate (255), which projects the surname's present-day count by applying the Census frequency rate to the current U.S. population.
What does 0.07 per 100,000 actually mean?
It is the Census Bureau's normalized frequency measure. A rate of 0.07 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 Mastny.
Has Mastny become more or less common over time?
Between 2010 and 2020, the surname Mastny went from 224 recorded bearers to 222. That is a decrease of 2 (-0.9%). In the national ranking it fell from #83,834 to #89,563.
What does the Census say about the background of Mastny?
Among Census respondents with the surname Mastny, the largest self-reported group is White at 90.1%. The next largest groups are Hispanic (4.1%) and Two or More Races (4.1%). 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 Mastny in the 2020 Census, accounting for 90.1% (200 people in the source table).
What is the full ancestry breakdown?
Mastny appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are White (90.1%), Hispanic (4.1%), Two or More Races (4.1%). 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 Mastny (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 Mastny mean?
A surname likely derived from the Czech word "mastný" meaning greasy or oily. 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 Mastny (0.07 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 people have the surname Mastny?
HowManyOfMe.org, our sister site, answers that with the living-bearer count in one glance.