How Many People Are Named William Diefenderfer?
There are approximately 6 people named William Diefenderfer living in the United States today. That makes this name combination very rare, occurring at a rate of about 1 in 57,125,723 Americans.
This estimate combines SSA birth records for the first name William with Census Bureau frequency data for the surname Diefenderfer. Below you will find a breakdown of both names, including popularity trends, gender data, and ancestry information.
Estimated People with This Name
6
1 in 57,125,723 Americans
Combination Rarity
Very Rare
First Name
View full profileWilliam
Last Name
View full profileDiefenderfer
William: Popularity Over Time
Year-by-year SSA birth registrations for the first name William. The peak year was 1947 with 67,155 births. The average person named William today is 54 years old.
Ancestry of the Diefenderfer Surname
Self-reported race and ethnicity breakdown for people with the surname Diefenderfer, from the 2010 U.S. Census Bureau.
How we calculated this
The first name "William" has an estimated frequency of 0.681% among living Americans, based on SSA birth records from 1880 to 2024 adjusted for mortality using CDC 2023 life tables.
The surname "Diefenderfer" appears at a rate of 0.25 per 100,000 people in the 2010 U.S. Census.
Multiplying these frequencies against the U.S. population of ~343 million gives 6 estimated people. This assumes first names and last names are statistically independent. Full methodology.
Other people named William
Other people with the surname Diefenderfer
William Diefenderfer: Questions and Answers
How many people are named William Diefenderfer?
We estimate approximately 6 people named William Diefenderfer are alive in the United States today. The first name William is shared by 2,335,115 Americans, and the surname Diefenderfer is shared by 857.
How rare is the name William Diefenderfer?
This name combination is classified as Very Rare, occurring at a rate of about 1 in 57,125,723 Americans. The first name William is very common and the surname Diefenderfer is very rare.
Is William a male or female name?
William is predominantly male, with 99.6% of bearers being male and 0.4% female. It peaked in popularity in 1947 and the average bearer today is 54 years old.
Where does this data come from?
First name data comes from the Social Security Administration (1880 to 2024), adjusted for survival using CDC 2023 life tables. Surname data comes from the 2010 U.S. Census Bureau. Full methodology.
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