For a monthly subscription, Fincent calculates a 3-month average of your expenses at the end of each month.

For an annual subscription, Fincent calculates a 12-month average of your expenses at the end of each annual term.

You can view you expenses from your P&L. Total expenses are derived from summation of COGS, Expenses and Other Expenses from you P&L.  

You can always view your current pricing plan and access receipts in Settings > Billing.