Kai is a popular boys' name in England & Wales, ranking #100 in 1998 with 528 recorded births. The name reached its all-time peak in 2010 with 1,308 births ranking #56. Since 1996, the popularity has increased by 149.1%. In 1998, approximately 1 in every 588 boys born was named Kai. STABLE Recent data shows the name is currently stable.
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.