Humanverse

Kailey vs Kaizen

American parents have registered 27,254 Kaileys since 1880, against 3,070 Kaizens. But in 2025 it was Kaizen that was commoner, 900 babies to 153.

Babies given each name, 1880–2025

Births per year: Kailey against Kaizen, 1880 to 2025 0 400 800 1.2k 1.6k 1880 1900 1920 1940 1960 1980 2000 2020

Kailey Kaizen

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

Of the 48 years in which either name was published, Kailey for 44 years and Kaizen for 4 years. The lead changed hands once.

Side by side

  Kailey Kaizen
Total US births 27,2543,070
Most in one year 1,449900
Babies in 2025 153900
Estimated living today 27,0003,100
Median age today 212
Peak year 20042025
Best rank 228th girls364th boys
Rank in 2025 1,417th364th
First recorded 19702004
Girls / boys 27,244 / 1031 / 3,039

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 Kaileys alive today are over 21; half the Kaizens are over 2. That is 19 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 Kailey Kaizen
England and Wales 146101
France 40 Kaïley30

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: Kailey and Kaizen.