For informational purposes only. Not financial, investment, or tax advice. Results are estimates based on the inputs provided. Consult a qualified financial professional before making financial decisions.
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How this calculator works
Use the explanation to understand the formula, assumptions, and practical limits behind the calculator result.
How Credit Card Interest Accrues Daily
Unlike installment loans, credit card interest compounds on your average daily balance:
- APR: Annual Percentage Rate — the annual cost of carrying the balance
- Daily rate: APR ÷ 365, applied to each day's ending balance
- Billing cycle interest: sum of daily interest across all days in the cycle
For a USD 5,000 balance at 22% APR: daily interest ≈ USD 5,000 × (22% ÷ 365) = $3.01/day — USD 90/month before any payment lands.
The Minimum Payment Trap
Minimum payments are typically set at 1–2% of the balance or USD 25–35 — whichever is greater. At 22% APR on a USD 5,000 balance:
| Monthly Payment | Payoff Time | Total Interest |
|---|---|---|
| Minimum (2%) | 24+ years | USD 7,200+ |
| USD 150 | 4 years 7 months | USD 3,105 |
| USD 200 | 2 years 11 months | USD 1,921 |
| USD 300 | 1 year 10 months | USD 1,155 |
| USD 500 | 10 months | USD 635 |
Raising the payment from minimum to USD 200 — often less than a single dinner out per week — cuts payoff time by over 21 years and saves $5,279 in interest.
The minimum payment trap in one number: Paying 2% minimum on a USD 5,000 balance at 22% APR takes 24+ years and costs USD 7,200 in interest — more than the debt itself. Minimum payments are usually too small to pay balances down quickly.
Payoff Timeline Formula
- = months to payoff
- = monthly rate = APR ÷ 12
- = current balance
- = fixed monthly payment (must be greater than to make progress)
If your payment does not exceed the monthly interest charge, the balance grows indefinitely.
Frequently asked questions
How is credit card interest calculated if I carry a balance?
Credit card issuers use the Average Daily Balance method. Each day's balance is recorded, summed across the billing cycle, divided by the number of days, then multiplied by the daily periodic rate (APR ÷ 365) and by the number of days in the cycle. Making a payment mid-cycle lowers the average daily balance and reduces the interest charge for that month. If you pay the full statement balance by the due date each month, you are in the grace period — no interest accrues at all, making credit card debt the most expensive form of borrowing only for those who carry balances.
What happens if I only make minimum payments?
Minimum payments are usually designed to keep the account current, not to eliminate the balance quickly. Paying 2% of a USD 5,000 balance at 22% APR takes 24+ years and costs more than USD 7,000 in interest — more than the original balance. The reason it takes so long is that minimum payments shrink as the balance falls, so the payment amount continuously decreases while interest still accrues on most of the remaining balance. Committing to a fixed payment amount (not the minimum) is the single most effective change most cardholders can make.
Should I do a balance transfer to a 0% promotional card?
A 0% balance transfer can reduce interest if you can repay the balance before the promotional period ends. Compare the transfer fee with the interest you would otherwise pay, and divide the balance by the remaining promo months to find the payment needed to clear it before the standard APR resumes.
Does carrying a small balance help my credit score?
No — this is one of the most persistent myths in personal finance. Carrying a balance does not help your credit score in any way. Your credit utilization ratio (balance ÷ credit limit) is what matters, and lower utilization is always better for your score. Paying your full statement balance each month by the due date keeps utilization manageable and costs zero interest. The myth may persist because people confuse 'active account' with 'carrying a balance' — what helps credit is using the card regularly and paying on time, not owing money.
