Louis Pasteur
There are approximately 1 people named Louis Pasteur living in the United States today. That makes this name combination very rare, occurring at a rate of about 1 in 342,754,338 Americans.
This estimate combines SSA birth records for the first name Louis with Census Bureau frequency data for the surname Pasteur. Below you will find a breakdown of both names, including popularity trends, gender data, and Census demographics where available.
Expected bearers
1
1 in 342,754,338
Named Louis
183K
Alive today
Named Pasteur
388
Alive today
US population
343M
Denominator
Estimated living: 183K
Rarity: Common
Gender: Male
Peak year: 1921
Average age: 56
Top Census group: White (64.6%)
Estimated bearers: 388
Rarity: Very Rare
Census rank: #63,720
Per 100K: 0.11
Top ancestry: Black (54.7%)
First name trend
Louis: popularity over time
Year-by-year SSA birth registrations for the first name Louis. The peak year was 1921 with 7,296 births. The average person named Louis today is 56 years old.
Babies born per year
Demographics
Ancestry and ethnicity for Louis
Self-reported race and ethnicity breakdown for people with the first name Louis, from the 2020 US Census Bureau first-name tables. The largest published group is White at 64.6%.
The bar chart below shows how people with the first name Louis described their own race and ethnicity on the 2020 Census form. These are self-reported numbers, and they describe the population who happened to carry the name Louis at the time of the Census. A first name does not determine a person's race or ethnicity.
- White64.6% · 118,544
- Hispanic or Latino17.9% · 32,861
- Black or African American12.3% · 22,641
- Asian and Pacific Islander2.2% · 4,089
- Two or more races2.1% · 3,923
- American Indian and Alaska Native0.7% · 1,314
Ethnicity
Ancestry of the Pasteur surname
Self-reported race and ethnicity breakdown for people with the surname Pasteur, from the 2020 US Census Bureau. The largest group is Black at 54.7%.
The bar chart below shows how people with the surname Pasteur described their own race and ethnicity on the 2020 Census form. These are self-reported numbers, and they describe the population who happened to carry the surname Pasteur at the time of the Census. A surname does not determine a person's race or ethnicity.
- Black or African American54.7% · 185
- White40.5% · 137
- Two or more races3.6% · 12
- Hispanic or Latino0.9% · 3
- Asian and Pacific Islander0.3% · 1
Methodology
How we calculated this
The first name Louis has a living-bearer frequency of 0.0533% of the US population, based on 182,628 estimated living Americans carrying this first name (from SSA birth records going back to 1880, adjusted for mortality using CDC life tables).
Even though the Census Bureau now publishes first-name tables, we do not use that file as the main first-name input for this estimate. The latest first-name Census snapshot is from 2020, which makes it 6 years old today. Because Census first-name data is only released once every 10 years, SSA birth records plus CDC survival rates give a better current estimate of how many people are likely alive with the name Louis right now.
The surname Pasteur appears at a rate of 0.11 per 100,000 residents in the 2020 Census Bureau surname file, which translates to a frequency of 0.0001%.
Multiplying these two independent frequencies against the current US population of 342,754,338 gives an expected count of approximately 1 people with the full name Louis Pasteur. This assumes statistical independence between first and last names, which is a simplification but produces reasonable estimates for most combinations.
Related
Other people named Louis
FAQ
Louis Pasteur: questions and answers
How many people are named Louis Pasteur?
We estimate approximately 1 people in the United States share the full name Louis Pasteur. That works out to about 1 in 342,754,338 Americans. This is calculated by combining the first-name frequency (0.0533%) with the surname frequency (0.11 per 100K) against the current US population.
How rare is the name Louis Pasteur?
We classify Louis Pasteur as "Very Rare". About 1 in 342,754,338 Americans share this exact first and last name combination.
Is Louis a male or female name?
Louis is predominantly male. Out of 407,900 total SSA registrations, 99.3% were male and 0.7% were female. See the full Louis profile for detailed gender data.
Where does this data come from?
First-name data comes from the Social Security Administration's national baby name files (1880 to 2024). Surname data comes from the 2020 US Census Bureau decennial surname tables. Living-bearer estimates use CDC actuarial life tables to adjust for mortality. Read the full methodology.
How many people are named Louis Pasteur?
If you just want to know how many people are called Louis Pasteur, HowManyOfMe.org gives you the headline number in one glance.