The Number They Hope You Never Understand
Every credit card statement shows an APR — usually between 18% and 29%. Most people treat it as an abstract label. But APR is the single number that determines how much your debt costs every month, and credit card companies count on the fact that almost nobody does the math.
Your issuer takes the APR and divides by 365 to get a daily periodic rate. A 24% APR becomes roughly 0.0658% per day. That rate gets applied to your average daily balance — not your statement balance, not your minimum payment, but an average of what you owed each day during the billing cycle.
Why Minimum Payments Keep You in Debt
Carry a $5,000 balance at 24% APR and make only minimums, and the Credit Card Calculator on DebtCalc shows it takes over 25 years to pay off — costing more than $8,000 in interest. That's more than the original balance. Minimums are set at 1–2% of the balance or $25, whichever is higher. Most of your payment covers interest while principal barely moves.
The Grace Period Trap
Most cards offer a 21-to-25-day grace period where no interest accrues on new purchases — if you paid the previous statement in full. But the moment you carry any balance, the grace period disappears. Every new purchase starts accruing interest immediately. This is why partial payments cost more than people expect.
Running Your Own Numbers
Open the Credit Card Calculator and enter your current balance, APR, and what you can pay monthly. Try different payment amounts — even an extra $50 per month can cut years off the timeline and save thousands. Credit Karma's free score monitoring helps track how your utilization ratio improves as you pay down the balance.