Actually it depend on our hair length and thickness. However, we can start with a dime-sized amount for short to medium-length hair and increase as needed for longer or thicker hair. Here my tips is- if we find that our hair feels weighed down or looks greasy, we may have applied too much. Conversely, if our hair still feels dry or lacks moisture, we may need to use a bit more.  Just adjust the amount of conditioner based on our hair's length and thickness.