Been out of school for awhile - how do you calculate the finance charges for a credit card?

Question

I have an average daily balance, the interest rate, the daily periodic rate, and the finance charges accrued for the month...but try as I might, I can't tie back into the bank's figure that they billed me for.

What is the blasted formula for calculating this mess????

(For those of you smart enough not to use credit cards and live within your means instead....trust me. You may live more simply, but you are WAY better off than those of us who are in the pit.....)

To those who are great at basic math - whether you are in debt or not - thanks for your help!

Answer 1

It looks like you may be missing the number of days in the billing cycle.  Avg Daily Balance * Daily Periodic Rate * Number of Days in Billing Cycle.

Answer 2

And search the fine print--on my credit card, the finance charges apply to TWO months of balances.  Meaning if I carry a balance in month 1, pay off at month 2, don't use in month 3, that I still owe a finance charge in month 3.