2000
#107,038
National surname rank
Recorded bearers 154
First available Census row
Per 100,000 0.06
Very Rare Last name
Iwahashi
A Japanese surname possibly derived from elements meaning "rock" and "bridge."
According to the 2020 US Census Bureau surname tables, roughly 141 Americans carry the last name Iwahashi. That puts it at #139,785 in the national surname ranking, appearing at a frequency of 0.04 per 100,000 people (about 1 in 2,430,882 residents).
This page is the full Name Census profile for the Iwahashi 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
141
1 in 2,430,882
Census rank
#139,785
2020 decennial data
Per 100,000
0.0
Frequency rate
Recorded bearers
123
very rare in the US
Popularity narrative
The Census Bureau recorded 123 bearers of the surname Iwahashi in its 2020 decennial surname file. At a rate of 0.04 per 100,000 residents, it holds the 139785th position in the national surname ranking.
Among Census respondents with the surname Iwahashi, the largest self-reported group is Asian/Pacific Islander at 83.7%. The next largest groups are Two or More Races (11.4%) and White (3.3%).
Origin
Meaning and origin of Iwahashi
The surname Iwahashi has its roots in Japan, originating during the Kamakura period (1185-1333 CE). It is derived from the Japanese words "iwa" meaning rock or stone, and "hashi" meaning bridge or footbridge. This suggests that the name may have been initially associated with a location near a stone bridge or rocky area where a bridge was constructed.
One of the earliest recorded mentions of the Iwahashi name can be found in the Azuma Kagami, a historical record compiled during the late Kamakura period. This text documents various events and figures from the time, potentially including early bearers of the Iwahashi surname.
In the Muromachi period (1336-1573 CE), there are records of an Iwahashi family residing in the Echizen Province, located in present-day Fukui Prefecture. This family may have played a role in local administration or military affairs during that era.
During the Edo period (1603-1868 CE), the Iwahashi name appeared in various domains across Japan. One notable figure was Iwahashi Masayoshi (1619-1688), a samurai and military strategist who served under the Tokugawa shogunate.
In the late 19th century, Iwahashi Katsumi (1850-1917) was a prominent educator and pioneer of women's education in Japan. She founded one of the first private schools for girls in Tokyo, paving the way for greater educational opportunities for women.
Another individual of historical significance was Iwahashi Masaru (1891-1987), a renowned archaeologist and anthropologist who made significant contributions to the study of Japanese prehistory and the Jomon culture.
Throughout the 20th century, the Iwahashi surname continued to be associated with notable figures in various fields. Iwahashi Kiyoshi (1925-2008) was a renowned artist and sculptor, known for his abstract and avant-garde works.
While the Iwahashi name originated in Japan, it has since spread to other parts of the world through migration and cultural exchange. However, its deep roots and historical significance remain closely tied to its Japanese origins.
Demographics
Ancestry and ethnicity for Iwahashi
Among Census respondents with the surname Iwahashi, the largest self-reported group is Asian/Pacific Islander at 83.7%. The next largest groups are Two or More Races (11.4%) and White (3.3%).
The bar chart below shows how Iwahashi 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 Iwahashi surname at the time of the 2020 Census, not any inherent property of the name itself.
- Asian and Pacific Islander83.7% · 103
- Two or more races11.4% · 14
- White3.3% · 4
- Hispanic or Latino1.6% · 2
Timeline
Historical Census data for Iwahashi
Iwahashi 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
#116,829
National surname rank
Recorded bearers 149
-5 bearers (-3.2%)
Per 100,000 0.05
Rank movement Down 9,791 places
2020
#139,785
National surname rank
Recorded bearers 123
-26 bearers (-17.4%)
Per 100,000 0.04
Rank movement Down 22,956 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2000 | #107,038 | 154 | 0.06 | First available Census row | First available Census row |
| 2010 | #116,829 | 149 | 0.05 | -5 bearers (-3.2%) | Down 9,791 places |
| 2020 | #139,785 | 123 | 0.04 | -26 bearers (-17.4%) | Down 22,956 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 Iwahashi 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 | #116,829 | #139,785 | -19.6% |
| Count | 149 | 123 | -17.4% |
| Per 100K | 0.05 | 0.04 | -17.7% |
Between the 2010 and 2020 Census, the number of Iwahashi bearers went from 149 to 123 (-17.4% change). The surname moved down 22,956 positions in the national ranking, going from #116,829 to #139,785.
FAQ
Iwahashi surname: questions and answers
How many people in the U.S. have the surname Iwahashi?
Name Census estimates that about 141 living Americans carry the surname Iwahashi. Using the current population baseline, that works out to roughly 1 in 2,430,882 residents.
How common is Iwahashi?
Iwahashi ranks #139,785 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 123 people with the surname Iwahashi. That is different from the site's living-bearer estimate (141), 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 Iwahashi.
Has Iwahashi become more or less common over time?
Between 2010 and 2020, the surname Iwahashi went from 149 recorded bearers to 123. That is a decrease of 26 (-17.4%). In the national ranking it fell from #116,829 to #139,785.
What does the Census say about the background of Iwahashi?
Among Census respondents with the surname Iwahashi, the largest self-reported group is Asian/Pacific Islander at 83.7%. The next largest groups are Two or More Races (11.4%) and White (3.3%). 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 Iwahashi in the 2020 Census, accounting for 83.7% (103 people in the source table).
What is the full ancestry breakdown?
Iwahashi appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are Asian/Pacific Islander (83.7%), Two or More Races (11.4%), White (3.3%). 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 Iwahashi (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 Iwahashi mean?
A Japanese surname possibly derived from elements meaning "rock" and "bridge." 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 Iwahashi (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 Iwahashi?
For a quick modern estimate, our sister site HowManyOfMe.org answers that in one glance, with the living-bearer count front and centre.