Kai is a distinctive girls' name in United States, ranking #1280 in 1999 with 144 recorded births. The name reached its all-time peak in 2021 with 371 births ranking #769. Since 1996, the popularity has increased by 65.5%. In 1999, approximately 1 in every 12,318 girls born was named Kai. FALLING Recent data shows the name is currently falling.
Kai is one of those names with several genuine origin routes rather than just one. In European use Behind the Name marks its meaning as uncertain, while other established traditions use Kai separately with their own meanings.
The name spread widely across Europe and then the English-speaking world, but it also exists as a separate name in other languages. Because these traditions are independent, it is more accurate to describe Kai as multi-origin than to force one neat definition onto it.