Castor: Name Popularity, History & Rankings (1880

Rank 2025

#4,734

among boys · ↑1,511 vs 2024

Babies in 2025

named Castor

How common

1 in 81,337

boys born in 2025

Peak year

2016

29 babies

All-time total

390

#9,172 all-time among boys

First recorded

1998

in Social Security records

Castor popularity over time

390 babies have been named Castor since 1998, according to official Social Security records. Switch measure to see births per year or the yearly rank.

Measure

Births per 1,000 babies of that sex, comparable across eras

By decade. Change compares yearly averages, so the current partial decade is on equal footing. Best rank is the name's best yearly rank within the decade.

Decade	Boys	Per year	Change	Best rank
1880s	–	–	–	–
1890s	–	–	–	–
1900s	–	–	–	–
1910s	–	–	–	–
1920s	–	–	–	–
1930s	–	–	–	–
1940s	–	–	–	–
1950s	–	–	–	–
1960s	–	–	–	–
1970s	–	–	–	–
1980s	–	–	–	–
1990s	19	2	–	#5,524
2000s	89	9	+368%	#6,385
2010s	176	18	+98%	#3,702
2020s (to 2025)	106	18	0%	#3,941

Where Castor is heading

A five-year projection from the recent trend in births per 1,000 boys (damped so it flattens over time), converted to babies at today's birth totals. The implied rank places that projection in the 2025 field. A projection, not a promise: real trends bend.

Year	Projected babies	Per 1,000 boys	Implied rank
2026	20	0.01	outside top 500
2027	19	0.01	outside top 500
2028	18	0.01	outside top 500
2029	18	0.01	outside top 500
2030	17	0.01	outside top 500

The story of Castor

Castor is rare for boys in the United States, ranked #4,734 in 2025 with 21 babies given the name. It is currently holding steady compared with a decade ago.

Since 1998, 390 American babies have been named Castor. Its peak came in 2016, when 29 newborns received the name, the signature sound of the 2010s.

The chart above shows the full history: the popularity view (births per 1,000 babies) is the honest comparison across generations, since total US births have changed enormously since 1880. Switch to the rank view to see where Castor stood among all boys' names in any year, or use the compare tool to plot it against other names.

How old are people named Castor?

The median living Castor is about 9 years old; half are between 5 and 16. An estimated 400 people named Castor are alive in the United States today.

Estimated from births per year and Social Security period life tables; an approximation of the living age distribution, by age in years.

Castor year by year

Every year since 2001, and five-year steps back to 1880. Rank is within each sex.

Year	Boys	Boys rank
2025	21	#4,734
2024	14	#6,245
2023	11	#7,363
2022	17	#5,475
2021	17	#5,375
2020	26	#3,941
2019	23	#4,353
2018	24	#4,251
2017	14	#6,100
2016	29	#3,702
2015	17	#5,336
2014	18	#5,095
2013	17	#5,201
2012	15	#5,758
2011	10	#7,598
2010	9	#8,253
2009	13	#6,491
2008	8	#9,134
2007	8	#9,046
2006	11	#6,985
2005	9	#7,730
2004	6	#10,165
2003	7	#8,802
2002	8	#7,757
2001	9	#7,010
2000	10	#6,385
1995	–	–
1990	–	–
1985	–	–
1980	–	–
1975	–	–
1970	–	–
1965	–	–
1960	–	–
1955	–	–
1950	–	–
1945	–	–
1940	–	–
1935	–	–
1930	–	–
1925	–	–
1920	–	–
1915	–	–
1910	–	–
1905	–	–
1900	–	–
1895	–	–
1890	–	–
1885	–	–
1880	–	–

Frequently asked questions

Quick answers about Castor, drawn from the same Social Security data as the charts above.

How old is the average Castor?

The median living Castor is about 9 years old. Half of all living Castors are between 5 and 16 years old.

How many people named Castor are alive today?

An estimated 400 people named Castor are alive in the United States, based on 390 recorded births and Social Security life tables.

How popular is the name Castor in 2025?

Castor ranked #4,734 among boys' names in the United States in 2025, with 21 babies given the name, according to Social Security Administration data.

How many people are named Castor?

390 babies have been named Castor in the United States since 1998, based on Social Security card applications.

When was the name Castor most popular?

Castor peaked in 2016, when 29 newborns received the name.

Is Castor a boy or girl name?

Castor is overwhelmingly a boy's name: 100% of babies with the name.

Is the name Castor rising or falling?

Castor has been roughly stable over the past decade.

Will Castor become more popular?

Castor is trending downward. If the recent trend holds, we project roughly 17 boys named Castor in 2030, which would rank outside the top 500. Forecasts assume the current trend continues and become less certain further out.

Names like Castor

Names that sound and feel close to Castor: shared sounds, similar era, similar popularity. Each links to its full history.

Compare Castor with similar names → More names starting with C →