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Financial Literacy

Financial Literacy

Home Financial Literacy Credit and Debit The Balances Used to Calculate Your Interest

The Balances Used to Calculate Your Interest

Adjusted Balance

Your adjusted balance is pretty simple to calculate:

1. The month’s beginning balance is carried over from last month’s ending balance.
2. Add any bodacious buys you’ve made that month.
3. Subtract the payments you’ve made.
4. Ta-da! You get the Adjusted Balance.

Credit card companies don’t like to use this method because you get to deduct your payments before interest is charged, which means they get less money from you.

Previous Balance

Some credit card companies use your balance at the end of the past month to calculate interest. This is to your disadvantage because your balance is highest right before you make a payment.

Average Daily Balance

The average daily balance method is the most common way credit card companies charge interest. They look at all the charges you’ve made in a month and use those to calculate a weighted average daily balance.

Calculating your average daily balance

Beginning balance

You charge $200 on the 26th day of the month

Calculate a weighted average based on these amounts and days

Daily Balance# of DaysExtended
Days with a $3,000 balance
Days with a $3,200 balance ($3,000 plus the new $200)

Divide by the numbers of days in the billing cycle


Average daily balance


Monthly interest rate


Finance charge


Then they charge interest based on that average balance. Like, for Clive Clueless, his interest is 18% a year or 1½% a month (0.18 divided by 0.12 = .015), so he would pay $45.50 a month if he hasn’t sweated profusely enough yet to get his balance down to a more manageable level.

It’s better to choose a card that does not charge interest daily because then you wind up paying interest on interest and those daily amounts can add up to big bucks.

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