Use the statement minimum, then test a repayment assumption
The minimum due and payment date come from your issuer. This tool compares two simplified rules: a fixed dollar payment, or a percentage of the opening balance subject to a dollar floor. It does not reproduce formulas that add interest, fees or past-due amounts on top of a percentage.
Monthly calculation
Interest = opening balance × APR / 100 / 12. Payment = selected minimum + extra, capped at balance plus interest. The remainder is carried into the next month. Unrounded amounts are used internally; displayed amounts round to cents. Rates stay constant, payments occur at month end, and there are no new purchases, fees or promotional-rate changes.
For example, $1,000 at 0% APR with a fixed $100 payment takes 10 months and incurs no interest. At 24% APR, the same opening balance incurs $20 in first-month interest. A $20 payment makes no progress; a $10 payment is insufficient. Neither case receives an invented payoff date.
Why the default percentage scenario takes so long
Under this specific model, $5,000 at 22% APR with a 2% minimum and $25 floor takes 968 months, with $43,419.49 interest. Adding $50 to each month’s minimum reduces this to 89 months and $4,138.06 interest. These are computed illustrations, not typical issuer outcomes: a formula adding interest to a principal percentage would give a different result.
Read the limits before comparing
- Use one balance and one APR. Do not substitute a purchase APR for cash advances or other balances at different rates.
- If the selected payment does not reduce debt, the tool stops and reports that condition. It never changes your payment to force progress.
- A 1,200-month cap is a calculation limit, not a payoff. Savings require both scenarios to finish. The displayed schedule shows only the first 60 months.
- Extra payments reduce interest under the stated assumptions. Balance-transfer fees, promotional expiry, payment timing and new charges can change the comparison.
Check your issuer’s calculation
The CFPB explains daily interest and different APR balances. This monthly model is an approximation. U.S. statement repayment disclosures have specific assumptions and exceptions under Regulation Z § 1026.7; use your statement and card agreement for your actual obligation.