Dictionary / Vocabulary / 馬鹿さ加減
ばかさかげん
extent of (one's) foolishness; degree of stupidity
Also written バカさ加減、ばかさ加減
私は彼が笑っているのを見てやっと自分のばかさ加減に気がついた。
It was not until I saw him laughing that I realized what a fool I had been.
あいつの馬鹿さ加減には、もう、あきれちゃうよ。
It constantly appalls me how stupid he can be.