The water in Japanese bathtubs comes up to your shoulders.
Japanese bathtubs are pretty deep, up to your shoulders.
1) The hot water in Japanese bathtubs comes up to your shoulders.
「日本の湯船のお湯は肩までくる。」
2) Japanese bathtubs are pretty deep, up to your shoulders.
「日本の湯船は肩にくるほど深い。」
up to one's shoulders で「肩まで」
ご参考になれば幸いです!