Caius
Caius was given to 254 boys in 2025, #927 among boys’ names; 2,329 Americans have been recorded with it since 1994 (Social Security Administration, published May 2026).
An estimated 2,310 Americans named Caius and born in the U.S. are alive in 2026 (99% of everyone recorded); the median is 7 years old and half are between 3 and 12.
Girls and boys together; gaps are years SSA did not record (fewer than 5 births).
Births of Caius by year: SSA national baby-name file, 1880-2025, published May 8, 2026. SSA’s notes on the data.
How popular is Caius?
#927 among boys’ names, 2025
Caius rose from #1,289 in 2015 to #927 in 2025 among boys’ names; its share of boys born rose from 0.07 to 0.15 per 1,000.
254 babies in 2025, the peak
Caius peaked in 2025, when 254 boys were given it, #927 among boys’ names. In 2024 it went to 206 boys.
| Year | Births | Rank | Per 1,000 boys |
|---|---|---|---|
| 2025 | 254 | #927 | 0.15 |
| 2024 | 206 | #1,060 | 0.12 |
| 2023 | 140 | #1,347 | 0.08 |
| 2022 | 150 | #1,282 | 0.09 |
| 2021 | 138 | #1,341 | 0.08 |
| 2020 | 156 | #1,209 | 0.09 |
| 2019 | 137 | #1,328 | 0.08 |
| 2018 | 130 | #1,361 | 0.07 |
| 2017 | 110 | #1,512 | 0.06 |
| 2016 | 153 | #1,224 | 0.08 |
Every recorded year (28)
| Year | Births | Rank | Per 1,000 boys |
|---|---|---|---|
| 2015 | 138 | #1,289 | 0.07 |
| 2014 | 124 | #1,377 | 0.06 |
| 2013 | 109 | #1,494 | 0.06 |
| 2012 | 74 | #1,923 | 0.04 |
| 2011 | 44 | #2,708 | 0.02 |
| 2010 | 49 | #2,519 | 0.03 |
| 2009 | 43 | #2,805 | 0.02 |
| 2008 | 27 | #3,837 | 0.01 |
| 2007 | 29 | #3,608 | 0.01 |
| 2006 | 15 | #5,553 | 0.01 |
| 2005 | 23 | #3,954 | 0.01 |
| 2004 | 14 | #5,531 | 0.01 |
| 2003 | 15 | #5,067 | 0.01 |
| 2002 | 13 | #5,432 | 0.01 |
| 2001 | 16 | #4,697 | 0.01 |
| 2000 | 10 | #6,374 | 0.01 |
| 1999 | 7 | #7,968 | under 0.01 |
| 1994 | 5 | #8,973 | under 0.01 |
Ranks and shares: boys’ names in each year’s SSA file; share of all boys SSA recorded that year.
Is Caius a boy’s or a girl’s name?
Caius has been recorded only for boys: SSA lists no girls with the name in 28 years of records (it lists a name only in years with 5 or more babies of a sex).
Girls and boys named Caius: the SSA national file counts each sex separately.
How many people are named Caius, and how old are they?
2,310 alive in 2026, estimated
That is 99% of the 2,329 Americans ever recorded as Caius. The median Caius alive today is 7 years old; half are between 3 and 12.
The 2020 Census counted 1,208 people named Caius (5 women and girls, 1,203 men and boys). SSA’s births carried forward to Census day, April 1, 2020, predict 1,314 born in the U.S. The Census count is 8% below that prediction.
Alive today, by age
Alive today, by generation
| Generation | Born | Alive |
|---|---|---|
| Millennials | 1981-1996 | 5 |
| Generation Z | 1997-2012 | 374 |
| Generation Alpha | 2013-2025 | 1,930 |
An estimate, not a count. SSA’s files count people born in the United States who received a Social Security number, so anyone born abroad is not in them; before 1937 most people got a number as adults, and their survival is counted from that age.
Living estimate: SSA births carried forward with the survival rates in SSA’s cohort life tables (2024 Trustees Report) for each birth year and sex. How the estimate is made. Count: Census Bureau, first names in the 2020 Census (released April 14, 2026; names reported 100 or more times, with the Bureau’s disclosure-avoidance adjustment).
Where are babies named Caius born?
The states with the most babies named Caius are California, Texas and Ohio, with 36% of its births recorded by state in 2025.
| State | Births 2025 | Rank, boys | vs. national |
|---|---|---|---|
| California | 30 | #809 | 0.9× |
| Texas | 28 | #896 | 0.7× |
| Ohio | 12 | #718 | 0.8× |
| Tennessee | 11 | #642 | 0.5× |
| North Carolina | 10 | #832 | 0.7× |
| Indiana | 10 | #627 | 0.7× |
| Pennsylvania | 9 | #861 | 0.8× |
| Minnesota | 8 | #594 | 0.8× |
| Maryland | 8 | #578 | 0.7× |
| Washington | 8 | #741 | 0.6× |
States: SSA state file, 1910-2025, published May 8, 2026; births count girls and boys together, and the rank is among boys’ names in the state in 2025. The file leaves out any state and year with fewer than 5 babies of the name, so small states are undercounted; each ratio compares the state’s births of Caius with the births its national share predicts year by year, for states with at least 100 births of the name.
Names spelled alike
Of these 6 names spelled alike, given to 16,703 babies since 1880, Caius is the second most given (14% of them). In 2025 it was given to 254 of their 1,025 babies (25%), again the second most given.
Spelled alike: names in the SSA national file with the same pattern of letters and sounds and at most two letters apart, and Wiktionary’s listed forms; births since 1880 and in 2025, and each name’s peak year, from the SSA national file, published May 8, 2026. Some are separate names, not spellings of one.
Names that rose and fell in the same decades as Caius
Names whose births rose and fell across the same decades, measured on each decade’s share of births.
Similar histories: each decade’s share of births, from the SSA national file, 1880-2025, published May 8, 2026. SSA’s notes on the data.
More about Caius and names like it
- Compare Caius and CassiusBirths, ranks, peak and the living estimate side by side.
- The most given names of the 2020sCaius peaked in 2025.
- California’s most given namesThe state where SSA recorded the most babies named Caius since 1910.
- The top names of 2025The year the most babies were named Caius.
- The names of Generation AlphaMost people named Caius alive today were born 2013-2025.
- Names starting with CMost given first.