The Expenses Calculator module will take into account the Monthly Expense Rate setting you have in your General Details module. It will then determine the number of campaign days that have passed since the last time you calculated expenses. Finally, it calculates a pro-rated amount of expenses that each character owes. I rationalize to players that this accounts for entertainment, repairing weapons and armor, medicines, spell components, etc.

The DMG suggests the Monthly Expense Rate be 100gp per level per month. I sometimes add other expenses. For instance, if my character are all renting rooms at the same inn, I can determine they are all paying the same 30gp for rent monthly and so increase the Monthly Expense Rate by 30gp.

Expenses = ( (Monthly Expense Rate x Character Level) / Days Passed )