2000
#134,929
National surname rank
Recorded bearers 115
First available Census row
Per 100,000 0.04
Very Rare Last name
Semanek
A surname derived from the Czech word "semeno" meaning seed or grain.
According to the 2020 US Census Bureau surname tables, roughly 127 Americans carry the last name Semanek. That puts it at #148,665 in the national surname ranking, appearing at a frequency of 0.04 per 100,000 people (about 1 in 2,698,853 residents).
This page is the full Name Census profile for the Semanek 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
127
1 in 2,698,853
Census rank
#148,665
2020 decennial data
Per 100,000
0.0
Frequency rate
Recorded bearers
111
very rare in the US
Popularity narrative
The Census Bureau recorded 111 bearers of the surname Semanek in its 2020 decennial surname file. At a rate of 0.04 per 100,000 residents, it holds the 148665th position in the national surname ranking.
Among Census respondents with the surname Semanek, the largest self-reported group is White at 91.0%. The next largest groups are Hispanic (3.6%) and American Indian/Alaska Native (1.8%).
Origin
Meaning and origin of Semanek
The surname SEMANEK is of Czech origin, emerging in the late 16th century. It is derived from the Czech personal name "Šemal," meaning "grey-haired" or "grey." The name likely originated as a nickname for someone with prematurely greying hair or an elderly person.
SEMANEK was initially concentrated in the areas of Bohemia and Moravia, which were part of the Kingdom of Bohemia during the Holy Roman Empire. Variations in spelling included Semanek, Semánek, and Šemánek, reflecting regional dialects and orthographic conventions of the time.
One of the earliest recorded instances of the surname SEMANEK appears in a 1598 parish register from the village of Hlubočky, near Olomouc in Moravia. The entry refers to a Jan SEMANEK, a blacksmith by trade.
In the 17th century, the SEMANEK name can be found in various historical records from Bohemia and Moravia, such as land registers, tax rolls, and court documents. Notable examples include Tomáš SEMANEK (1621-1689), a prosperous landowner in the village of Žižkov, and Kateřina SEMANEK (c. 1650-1718), a midwife in Prague.
During the 18th and 19th centuries, the SEMANEK surname spread beyond its traditional heartland as people migrated to other parts of the Austro-Hungarian Empire and beyond. Notable bearers of the name include:
1. Jakub SEMANEK (1778-1844), a Czech theologian and philosopher from Litoměřice.
2. František SEMANEK (1825-1894), a Czech painter and illustrator known for his portraits and landscapes.
3. Antonín SEMANEK (1844-1913), a Czech architect who designed several notable buildings in Prague.
4. Jaroslav SEMANEK (1884-1957), a Czech journalist and writer who published works on Czech history and culture.
5. Božena SEMANKOVÁ (1903-1976), a Czech artist and illustrator associated with the avant-garde movement.
The SEMANEK surname has a rich history dating back centuries, with its origins rooted in the Czech lands and a connection to personal characteristics and occupations. While not a widely distributed name, it has been borne by notable figures in various fields throughout history.
Demographics
Ancestry and ethnicity for Semanek
Among Census respondents with the surname Semanek, the largest self-reported group is White at 91.0%. The next largest groups are Hispanic (3.6%) and American Indian/Alaska Native (1.8%).
The bar chart below shows how Semanek 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 Semanek surname at the time of the 2020 Census, not any inherent property of the name itself.
- White91.0% · 101
- Hispanic or Latino3.6% · 4
- American Indian and Alaska Native1.8% · 2
- Two or more races1.8% · 2
- Black or African American0.9% · 1
- Asian and Pacific Islander0.9% · 1
Timeline
Historical Census data for Semanek
Semanek 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
#158,432
National surname rank
Recorded bearers 102
-13 bearers (-11.3%)
Per 100,000 0.03
Rank movement Down 23,503 places
2020
#148,665
National surname rank
Recorded bearers 111
+9 bearers (+8.8%)
Per 100,000 0.04
Rank movement Up 9,767 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2000 | #134,929 | 115 | 0.04 | First available Census row | First available Census row |
| 2010 | #158,432 | 102 | 0.03 | -13 bearers (-11.3%) | Down 23,503 places |
| 2020 | #148,665 | 111 | 0.04 | +9 bearers (+8.8%) | Up 9,767 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 Semanek 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 | #158,432 | #148,665 | 6.2% |
| Count | 102 | 111 | 8.8% |
| Per 100K | 0.03 | 0.04 | 23.8% |
Between the 2010 and 2020 Census, the number of Semanek bearers went from 102 to 111 (+8.8% change). The surname moved up 9,767 positions in the national ranking, going from #158,432 to #148,665.
FAQ
Semanek surname: questions and answers
How many people in the U.S. have the surname Semanek?
Name Census estimates that about 127 living Americans carry the surname Semanek. Using the current population baseline, that works out to roughly 1 in 2,698,853 residents.
How common is Semanek?
Semanek ranks #148,665 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 111 people with the surname Semanek. That is different from the site's living-bearer estimate (127), 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 Semanek.
Has Semanek become more or less common over time?
Between 2010 and 2020, the surname Semanek went from 102 recorded bearers to 111. That is an increase of 9 (+8.8%). In the national ranking it rose from #158,432 to #148,665.
What does the Census say about the background of Semanek?
Among Census respondents with the surname Semanek, the largest self-reported group is White at 91.0%. The next largest groups are Hispanic (3.6%) and American Indian/Alaska Native (1.8%). 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 Semanek in the 2020 Census, accounting for 91.0% (101 people in the source table).
What is the full ancestry breakdown?
Semanek appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are White (91.0%), Hispanic (3.6%), American Indian/Alaska Native (1.8%). 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 Semanek (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 Semanek mean?
A surname derived from the Czech word "semeno" meaning seed or grain. 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 Semanek (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 people share the surname Semanek?
For a quick modern estimate, our sister site HowManyOfMe.org answers that in one glance, with the living-bearer count front and centre.