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 ancestry information.
Expected bearers
1
1 in 342,754,338
Named Louis
183K
Alive today
Named Pasteur
343
Alive today
US population
343M
Denominator
Estimated living: 183K
Rarity: Common
Gender: Male
Peak year: 1921
Average age: 56
Estimated bearers: 343
Rarity: Very Rare
Census rank: #67,126
Per 100K: 0.10
Top ancestry: White (48.3%)
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
Ethnicity
Ancestry of the Pasteur surname
Self-reported race and ethnicity breakdown for people with the surname Pasteur, from the 2010 US Census Bureau. The largest group is White at 48.3%.
- White48.3%
- Black or African American43.2%
- Hispanic or Latino4.4%
- Two or more races4.1%
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).
The surname Pasteur appears at a rate of 0.10 per 100,000 residents in the 2010 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 (0.10 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 2010 US Census Bureau decennial surname tables. Living-bearer estimates use CDC actuarial life tables to adjust for mortality. Read the full methodology.