Cai
Masculine
Cai is given to both — 1,450 boys and 495 girls since 1880. See other names given to both
Cai is the Welsh Kay — Arthur's foster-brother and seneschal — and the name goes back to the Roman Gaius, whose meaning nobody has recovered.
How old is the name Cai?
Cai first appears in US birth records in 1989 — 36 years ago. The typical Cai is a kid of about 9 — this name's wave is very recent. About 1,400 people named Cai are estimated to be alive in the US today.
When was the name Cai most popular?
Cai peaked in 2022, reaching #1611 nationally. Today it ranks #2108, 497 places below that high. See the whole 2022 chart.
Lists built from the same records:
Where it comes from
From Gaius to Cai
The story of Cai
Cai appears in the earliest Welsh Arthurian material, older than the French romances, as Arthur's companion with supernatural attributes — he could go nine days without breathing and grow as tall as a tree. French romance turned him into Sir Kay, the rude steward. Cai is standard in Welsh naming and is in current American use.
Meaningscholars disagree
Not established
From the Welsh Cai, generally derived from the Latin Gaius, a very common Roman first name whose etymology is genuinely unrecovered. A Chinese Cai and a Vietnamese Cai are separate names. The Welsh-Latin route is documented; the Latin meaning is not.
How the name formed
- Gaius
- Cai
Related forms: Cai · Kay · Gaius
Pronouncing Cai
KY
One syllable. Cai and Kai are homophones in Welsh and English alike.
Nicknames for Cai
Moderate
What the data says
146 years of official birth records
The long climb, and where it stands now
The same years in position rather than babies
- First recorded
- 1989
- Most boys named
- 2022108 — the highest on record
- Peak rank
- #1611reached in 2022
- Change vs 2024
- −16.9%69 in 2025, from 83
Rank is a position, a count is a headcount, and they move independently — a name can hold its rank while the number of babies behind it falls. Source: U.S. Social Security Administration.
Cai in other languages
The same name elsewhere
- Cai in Welsh — same name
- Kay in English — related form
- Gaius in Latin — related form
Strongest US states over the last decade: Florida, Texas, California.
Cais among us
people named Cai are estimated to be alive in the US today
About 1 boy in 24,755 born in 2025 was named Cai
Estimated from SSA birth records and published actuarial life tables. Method
Spellings of Cai
- #2108
- Cai on the 2025 chart
- #85
- counting every spelling
The SSA counts spellings, not names. Cai went to 69 boys in 2025, but Kai and Khai are the same name said out loud. Together the 5 spellings went to 4,031, which makes it the 85th most-given boys’ name of the year — 2,023 places above the chart.
and 2 rarer spellings.
About 1 boy in 424 born in 2025 was given one of these spellings — against 1 in 24,755 for Cai itself.
Spellings are grouped by a fixed rule that folds interchangeable English spellings of one sound (ck/k, ph/f, x/ks, a non-initial y for i) and keeps vowels apart, so Sean and Shawn stay separate names. It errs towards splitting: a family here is never larger than the truth. SSA national data, 2025. Method
Is it right for you
What happens to a name after it peaks
The Armen test
Every popular name lives one long story — a climb, a peak, a slow settling back. Cai's later chapters haven't been written yet, so we borrowed them: Armen climbed just as high around 1929, and its whole arc is on record. Line the two peaks up, and Armen's path sketches the road Cai is walking now.
Cai sits in the calm middle of the cycle — neither chasing a wave nor sliding off one. Middle-of-the-cycle names age slowly and predictably.
A scored estimate from 146 years of naming cycles — not a prophecy. Great names outlive statistics. How this is scored
Where Cai is headed
Cai should hold steady through 2030 — the curve is flat, and flat curves are the most predictable kind.
Medium confidence — fitted on official counts through 2025.
A damped-trend projection of the official birth data — a sketch of momentum, not a promise. Every name's forecast, ranked.
Cai beside its neighbors
The names ranked closest to Cai in 2025, in babies rather than position — the bars are to scale.
US boys given each name in 2025.
The trade-off
- The earliest Welsh Arthurian material gives him supernatural powers, which is a first-rate detail.
- One syllable, clean, and never mispronounced.
- It is genuinely Welsh and has a continuous record there.
- Gaius's own meaning is genuinely unrecovered.
- Kai is far commoner in American use and identical in sound.
- It is very short and can be swallowed by a long surname.
Nobody names a baby alone.
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What they receive
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Cai
Masculine · #2108 in the U.S.
Frequently asked
- How many Cais are there in the world?
- No country counts the world's names, so there is no worldwide figure — anyone quoting one is estimating. About 1,400 people named Cai are estimated to be alive in the US today.
- How do you spell Cai?
- Cai is one of 3 recorded spellings. Kai is the more common one — 3,768 births in 2025 against 69 for Cai.
- How popular is the name Cai in 2025?
- Cai ranks #2108 among US boy names in 2025, with 69 babies given the name.
- How rare is the name Cai?
- About 1 in every 24,755 US boys born in 2025 was named Cai — 69 in all.
- Will my child share the name Cai with classmates?
- Cai will almost certainly be the only one in school.
Ranked beside Cai
Names sitting at a similar level of popularity right now.
Armoni#2108 · Ansh#2108 · Darryl#2108 · Ayven#2108 · Artist#2108 · Aero#2108 · Khyrie#2108 · Sameer#2108
Looking for what else is popular rather than what resembles Cai? See the current top 100.
Choosing between Cai and another name?
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US figures from the Social Security Administration. 1880–2025. Data & methodology
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