Credit Card Interest Calculator

Enter your balance, APR and monthly payment to see your payoff date and total interest — then nudge the payment up and watch the interest collapse.

Time to pay off
Total interest
Total paid
Interest as % of balance

How credit card interest actually works

Credit cards charge interest daily on your average balance: your APR divided by 365, applied every day, then billed monthly. At 20.99% APR, a $5,000 balance accrues roughly $87 of interest in the first month — so of a $200 payment, only about $113 reduces what you owe. That's why minimum payments feel like running on a treadmill.

The minimum payment trap

Minimum payments are typically 2–3% of the balance or interest plus a small fixed amount. Paying only the minimum on $5,000 at 21% APR can take well over 20 years and cost more in interest than the original balance. Fixing your payment at a set dollar amount (rather than the shrinking minimum) already cuts years off; raising it beats almost any other use of spare cash, because paying down 21% debt is a guaranteed 21% return.

Faster payoff strategies

  • Avalanche: pay minimums on everything, throw every spare dollar at the highest-APR card. Mathematically optimal.
  • Snowball: smallest balance first, for the motivational wins. Slightly costlier, often more sustainable.
  • Balance transfer / consolidation: a 0% promotional transfer or a lower-APR personal loan can save a lot — check the transfer fee and use our loan calculator to compare.

Frequently asked questions

Why does my payment barely reduce my balance?
Because interest accrues first. If your monthly interest is $87 and you pay $100, only $13 hits the principal. The results above show exactly how much of your total payments go to interest at your numbers.
How do I avoid credit card interest entirely?
Pay the full statement balance by the due date every month. Nearly all cards have a grace period on purchases — carry no balance, pay no interest. Note that cash advances usually accrue interest immediately with no grace period.
Does carrying a small balance help my credit score?
No — that's a persistent myth. Paying in full is best for both your score and your wallet. What helps your score is low utilization (balances below ~30% of limits) and perfect payment history.
What if my payment is less than the monthly interest?
Your balance grows forever — the calculator will warn you. You'd need to at least cover the monthly interest (balance × APR ÷ 12) plus something extra to make progress.