Calligraphy will make you know stroke order better. That may be about it. The only way to get good at writing kanji is to write kanji. It eventually will come to you.
Regular handwriting is almost all wrist and finger action. Neither of these play as big a role in calligraphy. Check out this guy writing beautifully to see how much importance arm movement plays in calligraphy (and compare it with how much is used in handwriting):
書道入門 筆の選びかた 大井錦亭 - YouTube
You might want to wait for an answer from Ryuurui, though. He's our resident calligraphy expert on the board.