Board Thread:Naruto Discussions/@comment-31099706-20170316100429/@comment-3965545-20170316215057

Kurama was split into yin and yang halves, Kurama's chakra levels were split in half, but not his power.. so Naruto has more chakra now.. combined with his Hashirama arm he now has his vitality and chakra levels go up even higher.

His size got smaller because he is a living chakra entity.. meaning the less chakra he has the smaller he gets.. therefor he was split in half, it didn't affect how strong he was, only how much chakra he had.