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Kai vs Kaisyn

American parents have registered 78,710 Kais since 1880, against 1,087 Kaisyns. Kai is still ahead, with 4,002 babies in 2025.

Babies given each name, 1880–2025

Births per year: Kai against Kaisyn, 1880 to 2025 0 1.5k 3k 4.5k 6k 1880 1900 1920 1940 1960 1980 2000 2020

Kai Kaisyn

Each line is every baby given the name that year, girls and boys added together — the only count that means the same thing for both names. A line breaks where the name fell below five babies in a year — the point at which the SSA stops publishing it — rather than being drawn through a figure nobody published. A single published year in a gap shows as a dot.

Who was ahead

Kai has been the commoner name in every year either was published, 1926 to 2025. The lead has never changed hands.

The closest they came was 2024, when Kai had 4,515 and Kaisyn had 112.

Side by side

  Kai Kaisyn
Total US births 78,7101,087
Most in one year 5,732116
Babies in 2025 4,00290
Estimated living today 78,0001,100
Median age today 85
Peak year 20222024
Best rank 59th boys1,599th boys
Rank in 2025 93rd1,919th
First recorded 19262009
Girls / boys 8,478 / 70,232232 / 855

A rank is a position within one sex’s list for one year, so the two rank rows are not subtracted from one another and the winning column is not marked on them. The living figure is a life-table estimate, not a count.

Which name is older

Half of the Kais alive today are over 8; half the Kaisyns are over 5. That is 3 years between them: two names in use at the same time, worn by two different generations.

Where each one is strongest

How much commoner the name is in that state than it is nationally, from births recorded since 1910.

Both names abroad

Countries whose statistics office publishes both names, so the comparison can be made somewhere other than the United States.

Country Kai Kaisyn
England and Wales 25,3293

Every spelling a country files separately is added together, over whatever years that country publishes — which is not the same range in any two of them, so read the columns against each other and not the rows.

Compare something else

Related comparisons

Social Security Administration birth records, 1880–2025, public domain. Full histories: Kai and Kaisyn.