Kaius
A masculine name of Latin origin with an uncertain meaning.
Name Census estimates that about 1,780 living Americans carry the first name Kaius. The name is used almost exclusively for boys. The average person named Kaius today is around 7 years old, and the year with the single highest number of Kaius births was 2020 (201 babies).
This page is the full Name Census profile for Kaius. Below you will find a gender breakdown showing how the name splits between male and female registrations, a year-by-year popularity chart stretching back to 1880, decade-level totals, the top US states for this name, its meaning and etymology, and a set of frequently asked questions with data-backed answers.
For a British comparison, Name Census UK has a UK baby-name profile for Kaius with official rankings and popularity over time.
Key insights
- • Kaius is a relatively new arrival in the SSA data. The average bearer is just 7 years old, meaning it gained most of its traction in the last two decades.
People living today
1.8K
~ 1 in 192,559 Americans
Peak year
2020
201 babies that year
Average age
7
years old
2024 SSA rank
#1,134
Tracked since 2005
Popularity
Kaius: popularity over time
The SSA tracks Kaius from the 2000s through to the 2020s, spanning 3 decades of birth certificate data. The biggest single decade for the name was the 2020s, with 932 total registrations. The name continues to be given at rates close to its all-time high, suggesting it has not yet fallen out of fashion.
Babies born per year
Decades
Kaius by decade
The table below breaks the full SSA timeline into ten-year windows. Each row shows how many male and female babies were given the name Kaius during that decade, along with a combined total. This is useful for spotting eras where the name surged or retreated.
Geography
Where Kaius' live
The SSA's state-level files cover 31 states and territories. California, Texas, Florida recorded the most babies named Kaius, while Nevada, New Jersey, Nebraska recorded the fewest. The average across all reporting states is about 31 registrations each.
Origin
Meaning and history of Kaius
Kaius is a masculine given name with roots in ancient Rome. It is derived from the Latin praenomen "Gaius", which was a very common name among Roman men during the time of the Roman Republic and Empire. The name Gaius is thought to have originated from an old Latin word meaning "to rejoice" or "to be happy".
The earliest known use of the name Kaius dates back to the 6th century BC, when it was borne by several prominent figures in ancient Roman history. One of the most notable was Gaius Julius Caesar, the famous Roman military leader, statesman, and author who played a crucial role in the events that led to the demise of the Roman Republic and the rise of the Roman Empire. He lived from 100 BC to 44 BC.
Another famous Roman who bore the name Gaius was Gaius Cassius Longinus, a Roman senator and one of the leaders of the conspiracy that assassinated Julius Caesar in 44 BC. He lived from around 86 BC to 42 BC.
In the early Christian era, the name Gaius was also used by several individuals mentioned in the New Testament and other early Christian writings. One such person was Gaius of Corinth, who is believed to have been one of the earliest converts to Christianity in that city and is mentioned in the Epistle to the Romans.
During the Middle Ages, the name Kaius remained in use, particularly among the nobility and ruling classes of various European countries. One notable figure from this period was Gaius Petronius, an Italian nobleman and writer who lived in the early 15th century and is known for his satirical work "Satyricon".
In more recent times, the name Kaius has been less common, but there have been a few individuals of note who have borne it. These include Kaius Hedenström, a Finnish explorer and cartographer who lived in the 19th century and made significant contributions to the mapping of Siberia and the Arctic regions.
People
Kaius + last name combinations
How many people share a full name with Kaius as the first name? Click a combination below to see the estimate, or search any pairing.
Related
Other names starting with K
Other first names starting with K with a similar number of bearers.
FAQ
Kaius: questions and answers
How many people in the U.S. are named Kaius?
Name Census puts the figure at roughly 1,780 living Americans. We arrive at this by taking every SSA birth registration for Kaius going back to 1880 and adjusting each cohort for expected survival using CDC actuarial life tables. The result is an age-weighted living-bearer count, not a raw birth total. That works out to about 1 in 192,559 US residents.
Is Kaius a common name?
We classify Kaius as "Rare". It ranks above 93.2% of all first names in the SSA dataset by living bearers. Across the full history of the data, 1,793 babies have been registered with this name.
When was Kaius most popular?
The single biggest year for Kaius was 2020, when 201 babies received the name. The fact that the average living Kaius is about 7 years old gives you a rough sense of which era contributed the most bearers who are still alive today.
What does the SSA popularity chart show?
The chart tracks births, not the number of people alive with the name today. Each point shows how many babies were given the name Kaius in that year. That makes it useful for spotting when the name rose, peaked, or faded.
Is Kaius a male name?
Yes, 100.0% of people registered as Kaius in the SSA data are male. You can see the full per-sex comparison in the gender distribution section above, which includes the latest year rank, birth count, and peak year for each sex.
Is Kaius still being used today?
Yes. The SSA still recorded Kaius in 2024, and the page above shows its latest-year rank where available. A name can be well past its peak and still remain in steady use, especially if it built up a large population over earlier decades.
Why can a name have a lot of living bearers even if it is not trendy now?
Because living-bearer counts and current baby-name popularity measure different things. A name like Kaius can build up a very large population over many decades, even if fewer parents are choosing it now than they did at its peak.
Where does this data come from?
First-name figures come from the Social Security Administration's national baby name files, which cover every name on a birth certificate from 1880 to 2024. Living-bearer estimates layer in CDC actuarial life tables broken out by sex to account for mortality. The population baseline (342,754,338) is the Census Bureau's latest national estimate. You can read the full calculation on our methodology page.
Does every first name have Census demographic data?
No. The public Census first-name release only covers names that met the Bureau's publication rules, so many rarer names in the SSA files do not have a published Census demographic snapshot. In those cases, the page still shows the SSA trend, gender history, and state data.
How many people are called Kaius?
You can see how many Americans are named Kaius on our sister site HowManyOfMe.org — same data roots, lighter UI.