How this credit card payoff calculator works
Month by month: interest = balance × (APR ÷ 12), payment covers interest first, the remainder cuts principal, repeat. The result flashes red logic when your payment is under the interest-only number (it can never clear). Real cards compound daily (the 0.0XX% daily rate ×365 equals your quoted APR), so this monthly model tracks within a few dollars for typical balances. Add new charges to the top of your model by increasing the starting balance.
Frequently asked questions
What's the fastest way to pay off a card?
For single-card debt, mathematically any payment above the interest-only amount works — this tool's floor is a fixed payment, so increase it and watch months drop non-linearly. For multiple cards, avalanche (highest APR first) saves most dollars; snowball (smallest balance first) wins on follow-through for many people.
Why does paying half as much take so much longer?
Amortization is non-linear near the interest floor: at $6,000 and 22.9% APR, a $250 payment clears in ~29 months, but $125 is barely above the $114/month interest — the same debt takes 80+ months and doubles the interest cost. Small payment cuts have outsized consequences.
Should I do a 0% balance transfer instead?
If you have good credit and can clear it inside the promo window (often 18–21 months, plus a 3–5% transfer fee), yes: a $150 fee is trivial against the thousands this simulation's interest shows. The trap is reverting to minimum payments when the promo rate jumps back.