Credit Card Interest Calculator
See exactly how much total interest you'll pay across your cards, under both the snowball and avalanche methods.
Quick answer
Credit card interest accrues roughly monthly at your APR ÷ 12 applied to your balance — a $5,000 balance at 22% APR accrues about $91.67 in interest in a single month alone, before any payment is applied. Enter your real cards below to see your exact total interest under both payoff methods, not just a single month's charge.
Your cards
Monthly budget
Fastest debt-free date
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Using the recommended method
Months to freedom
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Total interest paid
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Snowball
Smallest balance first
- Debt-free
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- Months
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- Interest
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Avalanche
Highest APR first
- Debt-free
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- Months
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- Interest
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Balance over time
Frequently asked questions
How is credit card interest calculated?
Most issuers charge interest monthly based on your APR divided by 12, applied to your balance. For example, a $5,000 balance at 22% APR accrues roughly $91.67 in interest in a single month before any payment. Many cards actually compound daily on your average balance, which works out close to this monthly approximation for most purposes.
How much total interest will I pay on my credit card debt?
It depends on your balance, APR, monthly budget, and payoff order — there's no single number. Enter your real cards below and the calculator shows your exact total interest under both the snowball and avalanche methods.
Does paying off my highest-APR card first really save interest?
Yes — since interest accrues in proportion to your APR and balance every month, leaving a high-APR balance sitting around longer costs more than leaving a low-APR one sitting. That's the entire logic behind the avalanche method.
Why does my interest charge change every month even if my balance doesn't?
If your balance stays roughly flat, it's usually because your payment is barely covering the new interest that accrued — very little is going toward the actual principal. That's the core problem with paying only the minimum on a high-APR card.
Related: the minimum payment calculatorand the avalanche method explained.