2000
#4,869
National surname rank
Recorded bearers 6,623
First available Census row
Per 100,000 2.46
Rare Last name
Mcmaster
A Scottish occupational surname referring to the son of a master craftsman or one who held a high office.
According to the 2020 US Census Bureau surname tables, roughly 7,526 Americans carry the last name Mcmaster. That puts it at #5,150 in the national surname ranking, appearing at a frequency of 2.20 per 100,000 people (about 1 in 45,543 residents).
This page is the full Name Census profile for the Mcmaster 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 Mcmaster with 1881 census detail, origin facts and modern UK distribution where available.
Bearers in the US
7.5K
1 in 45,543
Census rank
#5,150
2020 decennial data
Per 100,000
2.2
Frequency rate
Recorded bearers
6.6K
rare in the US
Popularity narrative
The Census Bureau recorded 6,563 bearers of the surname Mcmaster in its 2020 decennial surname file. At a rate of 2.20 per 100,000 residents, it holds the 5150th position in the national surname ranking.
Among Census respondents with the surname Mcmaster, the largest self-reported group is White at 88.5%. The next largest groups are Two or More Races (3.8%) and Black (3.5%).
Origin
Meaning and origin of Mcmaster
The surname McMaster originated in Scotland in the 13th century. It is a variant of the Gaelic name MacMastair, meaning "son of the master". The name likely originated in the Scottish Highlands, where the prefix "Mac" was commonly used to denote a patronymic surname.
One of the earliest recorded instances of the McMaster surname can be found in the Ragman Rolls of 1296, which documented those who swore allegiance to King Edward I of England. The name appears as "Gillemor M'Mastre", suggesting that the name was already established by this time.
The McMaster surname can also be traced back to the Clan MacMaster, a Scottish clan that held lands in Argyllshire and the Isle of Arran. The clan's progenitor is believed to have been a man named Maistre, who lived in the 13th century.
In the 16th century, the McMaster name appeared in the Records of the Privy Council of Scotland, which documented legal proceedings and government affairs. One notable figure was John McMaster, who was granted a charter for lands in Ayrshire in 1536.
Throughout history, there have been several notable individuals with the McMaster surname. One of the earliest was Sir John McMaster (c. 1350-1420), a Scottish knight who fought in the Battle of Otterburn in 1388. Another was Gilbert McMaster (1778-1854), a Scottish-born American businessman and politician who served as a member of the United States House of Representatives.
Other notable McMasters include:
1. Joseph McMaster (1824-1886), an Irish-born American businessman and philanthropist who founded the McMaster University in Hamilton, Ontario, Canada.
2. Erasmus Darwin McMaster (1837-1900), an American lawyer and politician who served as the 16th Lieutenant Governor of Missouri.
3. William McMaster (1811-1887), a Scottish-born Canadian businessman and philanthropist who co-founded the Canadian Bank of Commerce.
4. John Bach McMaster (1852-1932), an American historian and professor who wrote extensively on the history of the United States.
5. William Muir McMaster (1799-1880), a Scottish-born Canadian businessman and politician who served as a member of the Legislative Assembly of the Province of Canada.
The McMaster surname has also been associated with various place names in Scotland, such as McMaster Castle in Ayrshire and the village of McMaster in Dumfries and Galloway.
Demographics
Ancestry and ethnicity for Mcmaster
Among Census respondents with the surname Mcmaster, the largest self-reported group is White at 88.5%. The next largest groups are Two or More Races (3.8%) and Black (3.5%).
The bar chart below shows how Mcmaster 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 Mcmaster surname at the time of the 2020 Census, not any inherent property of the name itself.
- White88.5% · 5,808
- Two or more races3.8% · 249
- Black or African American3.5% · 229
- Hispanic or Latino3.0% · 198
- Asian and Pacific Islander0.9% · 60
- American Indian and Alaska Native0.3% · 19
Timeline
Historical Census data for Mcmaster
Mcmaster 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
#5,184
National surname rank
Recorded bearers 6,744
+121 bearers (+1.8%)
Per 100,000 2.29
Rank movement Down 315 places
2020
#5,150
National surname rank
Recorded bearers 6,563
-181 bearers (-2.7%)
Per 100,000 2.20
Rank movement Up 34 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2000 | #4,869 | 6,623 | 2.46 | First available Census row | First available Census row |
| 2010 | #5,184 | 6,744 | 2.29 | +121 bearers (+1.8%) | Down 315 places |
| 2020 | #5,150 | 6,563 | 2.20 | -181 bearers (-2.7%) | Up 34 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 Mcmaster 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 | #5,184 | #5,150 | 0.7% |
| Count | 6,744 | 6,563 | -2.7% |
| Per 100K | 2.29 | 2.20 | -4.1% |
Between the 2010 and 2020 Census, the number of Mcmaster bearers went from 6,744 to 6,563 (-2.7% change). The surname moved up 34 positions in the national ranking, going from #5,184 to #5,150.
FAQ
Mcmaster surname: questions and answers
How many people in the U.S. have the surname Mcmaster?
Name Census estimates that about 7,526 living Americans carry the surname Mcmaster. Using the current population baseline, that works out to roughly 1 in 45,543 residents.
How common is Mcmaster?
Mcmaster ranks #5,150 in the 2020 Census surname tables and is classified on this site as "Rare." The Census recorded the name at a frequency of 2.20 per 100,000 residents, which is about 2 people out of every 100,000.
How many people with this surname were counted in the Census?
The raw 2020 Census file counted 6,563 people with the surname Mcmaster. That is different from the site's living-bearer estimate (7,526), which projects the surname's present-day count by applying the Census frequency rate to the current U.S. population.
What does 2.2 per 100,000 actually mean?
It is the Census Bureau's normalized frequency measure. A rate of 2.20 per 100,000 means that if you picked a random group of 100,000 U.S. residents, you would expect about 2 of them to have the surname Mcmaster.
Has Mcmaster become more or less common over time?
Between 2010 and 2020, the surname Mcmaster went from 6,744 recorded bearers to 6,563. That is a decrease of 181 (-2.7%). In the national ranking it rose from #5,184 to #5,150.
What does the Census say about the background of Mcmaster?
Among Census respondents with the surname Mcmaster, the largest self-reported group is White at 88.5%. The next largest groups are Two or More Races (3.8%) and Black (3.5%). 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 Mcmaster in the 2020 Census, accounting for 88.5% (5,808 people in the source table).
What is the full ancestry breakdown?
Mcmaster appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are White (88.5%), Two or More Races (3.8%), Black (3.5%). 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 Mcmaster (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 Mcmaster mean?
A Scottish occupational surname referring to the son of a master craftsman or one who held a high office. 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 Mcmaster (2.20 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 Mcmaster?
For a faster, more casual read, check HowManyOfMe.org — our sister site built around that single question.