Katharine Isabelle
There are approximately 1 people named Katharine Isabelle 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 Katharine with Census Bureau frequency data for the surname Isabelle. 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 Katharine
27K
Alive today
Named Isabelle
1.3K
Alive today
US population
343M
Denominator
Estimated living: 27K
Rarity: Uncommon
Gender: Female
Peak year: 1982
Average age: 45
Estimated bearers: 1.3K
Rarity: Rare
Census rank: #22,334
Per 100K: 0.39
Top ancestry: White (78.3%)
First name trend
Katharine: popularity over time
Year-by-year SSA birth registrations for the first name Katharine. The peak year was 1982 with 947 births. The average person named Katharine today is 45 years old.
Babies born per year
Ethnicity
Ancestry of the Isabelle surname
Self-reported race and ethnicity breakdown for people with the surname Isabelle, from the 2010 US Census Bureau. The largest group is White at 78.3%.
- White78.3%
- Black or African American15.3%
- Hispanic or Latino3.3%
- Two or more races2.1%
- Unknown or suppressed1.0%
Methodology
How we calculated this
The first name Katharine has a living-bearer frequency of 0.0078% of the US population, based on 26,798 estimated living Americans carrying this first name (from SSA birth records going back to 1880, adjusted for mortality using CDC life tables).
The surname Isabelle appears at a rate of 0.39 per 100,000 residents in the 2010 Census Bureau surname file, which translates to a frequency of 0.0004%.
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 Katharine Isabelle. This assumes statistical independence between first and last names, which is a simplification but produces reasonable estimates for most combinations.
Related
Other people named Katharine
FAQ
Katharine Isabelle: questions and answers
How many people are named Katharine Isabelle?
We estimate approximately 1 people in the United States share the full name Katharine Isabelle. That works out to about 1 in 342,754,338 Americans. This is calculated by combining the first-name frequency (0.0078%) with the surname frequency (0.39 per 100K) against the current US population.
How rare is the name Katharine Isabelle?
We classify Katharine Isabelle as "Very Rare". About 1 in 342,754,338 Americans share this exact first and last name combination.
Is Katharine a male or female name?
Katharine is predominantly female. Out of 41,215 total SSA registrations, 0.0% were male and 100.0% were female. See the full Katharine 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.