Credit card interest is a daily meter, not a monthly bill. An $8,000 balance at 24% APR costs $5.26 every single day: about $160 a month and $1,920 a year, before a dollar of the debt itself gets paid.
Most people have never seen their own number. The calculator below shows it in seconds, along with how much of your current payment actually reaches the balance.
What you’ll learn
- Your interest cost per day, month, and year
- How much of your payment hits principal
- Your payoff time and total interest
- How daily compounding works
- Four ways to cut the cost
See what interest costs
Enter your balance and APR. Add your monthly payment to see where it goes and your total payoff cost. Your inputs are saved in your browser.
Credit Card Interest Calculator
Enter your balance and APR to see what carrying the balance costs per day, per month, and per year.
Every month the balance sits, the meter runs. Debt Driver builds your payoff plan in two minutes.
Get My Personalized Plan →How card interest works
Cards charge interest daily, not monthly. Your APR divided by 365 gives your daily rate, and it is applied to your average daily balance every day of the billing cycle. At 24% APR, that is about 0.066% per day, compounding on itself.
Two consequences follow. First, a stated 24% APR actually costs slightly more than 24% over a year because of daily compounding. Second, when you pay matters: a payment made early in the cycle lowers your average daily balance and quietly trims the interest charge, even if the amount is identical.
The daily cost of a balance
Here is the meter at 24% APR, the ballpark rate on many cards today:
| Balance | Per day | Per month | Per year |
|---|---|---|---|
| $2,000 | $1.32 | $40 | $480 |
| $5,000 | $3.29 | $100 | $1,200 |
| $10,000 | $6.58 | $200 | $2,400 |
| $15,000 | $9.86 | $300 | $3,600 |
| $20,000 | $13.15 | $400 | $4,800 |
Where your payment goes
Interest gets paid first, principal gets the leftovers. On $8,000 at 24%, the first $160 of any payment covers interest. Pay $250 and only $90 reduces the debt; 64 cents of every dollar went to the bank.
This is also why extra payments punch above their weight: the interest is already covered, so every extra dollar goes 100% to principal. Raising that $250 payment to $400 cuts the payoff from 4.3 years to 2.2 years and the total interest from $4,899 to $2,319. More than half the interest, gone, for $150 a month.
Want to see the meter hit zero? Debt Driver maps your payoff month by month.
Get My Personalized Plan →How to cut the cost
1.Pay more than the minimum
Every dollar above the interest charge goes straight to principal, which shrinks next month’s interest too. The effect compounds in your favor.
2.Pay early or twice a month
Interest is charged on your average daily balance. Paying right after payday instead of at the due date lowers that average and trims the charge for free.
3.Attack the APR itself
A five-minute call asking for a rate reduction works more often than people expect, and a 0% balance transfer can pause the meter entirely for 12 to 21 months.
4.Stop new charges on the card
Carrying a balance usually kills your grace period, so new purchases accrue interest from day one. Run daily spending elsewhere until the balance is gone.
FAQs
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Debt Driver builds your payoff plan, forecasts your debt-free date, and shows your interest cost falling every month until it hits zero.
Get My Personalized Plan →Debt Driver is a debt payoff planning app. We are not a lender, credit card issuer, or credit-counseling agency. The calculator and tables above are illustrative and for educational purposes only; issuers calculate interest using their own daily balance methods, and your statement is the authoritative source for your charges. Nothing here is financial, credit, or legal advice.