Example $5,000 · 24% APR · $150/month Run the calculator for your numbers
- Month-one interest
- ~$100
- Total interest
- ~$3,300
- Time to pay off
- ~5 years
Tap calculate to replace this with your balance, APR, and payment.
Credit Card Interest Calculator: See What Interest Really Costs
Interest is the price of carrying a balance. Enter your balance, APR, and monthly payment—we show your daily interest cost, month-one finance charge, total interest over payoff, and how much you save by paying more.
📖 Before you calculate
How credit card interest is calculated
When you carry a balance past your due date, your card issuer charges interest—a percentage of what you owe, expressed as APR (annual percentage rate). Most US cards use a daily periodic rate: APR ÷ 365, applied to your balance each day. Those daily amounts add up to your monthly finance charge on your statement.
Three numbers drive your interest cost:
- Balance — the higher it is, the more interest accrues each day.
- APR — a 24% card costs roughly twice the daily interest of a 12% card on the same balance.
- Payment size — if your payment only covers interest, your balance never shrinks and total interest can exceed what you originally borrowed.
Example: $5,000 at 24% APR earns about $3.29/day (~$100/month) in interest. Pay $100/month and every dollar goes to interest—zero principal reduction. Pay $150/month and ~$50 hits principal; total interest over payoff drops from thousands of dollars to a much shorter timeline. That is why this calculator leads with your interest charge, not just payoff time.
For issuer-specific minimum rules, use our minimum payment calculator. For a fixed payment plan and debt-free date, try the credit card payoff calculator. For the full formula breakdown, read how credit card interest works.
Calculate your interest cost
Enter balance, APR, and monthly payment—we show daily interest, total interest over payoff, and pay-more comparisons in one place.
Your interest breakdown and payoff results appear here after you calculate.
Your payment vs paying more
Card 1 shows total interest at your payment; card 2 shows how much interest you save by paying a bit more.
How credit card interest works — daily rates, finance charges, and why minimums barely dent principal.
Example Same debt · +$50/month Pay $200 instead of $150
- Total interest
- ~$1,700
- Interest saved
- ~$1,600 vs $150/mo
- Time to pay off
- ~2.7 years
Small payment bumps cut total interest dramatically.
Model note: we hold your payment steady for comparison. Real minimums shrink as your balance falls. See minimum vs fixed payment.
🚨 The interest trap
Why interest can cost more than your original debt
Credit card interest compounds against you when payments barely cover finance charges. At high APR, month-one interest on a $5,000 balance can be ~$100. Pay only $100/month and you are running in place—sometimes backward if new charges appear.
The painful part is total interest: paying near the interest-only level for years can cost more than the original purchase. Bump to $200/month on the same $5,000 balance at 24% APR and total interest can drop from ~$5,500 to under $2,000.
| Monthly payment | Month-one interest | Approx. total interest | Payoff time |
|---|---|---|---|
| $100 (interest-only) | ~$100 | Keeps growing | Never |
| $150 | ~$100 | ~$3,300 | ~5 years |
| $200 | ~$100 | ~$1,700 | ~2.7 years |
| $300 | ~$100 | ~$1,000 | ~1.6 years |
Wondering what your issuer minimum would cost in interest? Compare with the minimum payment calculator. For balance-specific guides, see how to pay off $5,000 or debt payoff scenarios.
❓ FAQ
Credit card interest questions answered
How is credit card interest calculated?
Most issuers use a daily periodic rate (APR ÷ 365) on your balance each day. Monthly finance charges sum those daily amounts. This calculator uses monthly amortization—enter balance, APR, and payment for your estimate. Read how interest works for the full breakdown.
How much interest does my card charge per month?
Month-one interest ≈ balance × (APR ÷ 12). $5,000 at 24% APR is about $100 the first month. Enter your balance and APR above—the calculator shows your exact month-one charge and daily cost.
How much total interest will I pay?
It depends on balance, APR, payment size, and how long you carry the debt. This tool projects total interest for a fixed monthly payment. At high APR with low payments, total interest can exceed your original balance.
What happens if I only pay the interest?
Your balance does not shrink. Unpaid interest can be added to your balance, so next month's charge grows. You need to pay more than month-one interest to make progress. See what happens if you only pay the minimum.
How can I pay less interest?
Pay more than the minimum, stop adding new charges while paying down, and explore lower-APR options if you qualify. Use the what-if scenarios in this calculator—$50 extra often saves thousands in total interest.
What is the daily interest cost?
Daily interest ≈ balance × (APR ÷ 365). On $5,000 at 24% APR, that is about $3.29/day. The calculator shows your daily cost based on your current balance.