Credit Card Interest Calculator: APR to Interest Cost

Inputs

Current balance Current statement balance / balance carried. APR

Annual Percentage Rate.

Days in billing cycle Common: 28–31 days (default 30). Average daily balance (optional) If blank, we assume average daily balance = current balance.

Projection (optional)

Monthly payment If blank/0, projection assumes no payments. New purchases per month Adds to balance each month (default 0).

Projection length

months

Default 12 months. Show schedule Full schedule can be long.

Results

Monthly interest estimate + projections.

Daily periodic rate

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Monthly periodic rate (approx)

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Estimated interest this cycle

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Total interest over projection

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Ending balance (projection)

—

Projection schedule

#	Balance start	Purchases	Interest	Payment	Balance end
Run a calculation to see the schedule.

Note: This is an estimate. Real issuers may compute interest daily and apply payments on specific dates.

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