How long a credit card balance actually takes to pay off
A credit card balance doesn't shrink at a steady pace just because you're paying every month — interest is charged first, and only what's left of the payment reduces what you owe. At a high APR and a small payment, most of it can go straight to interest for months at a time.
The mechanics
Each month the issuer adds that month's interest to the balance, then subtracts your payment. If the payment barely exceeds that month's interest, the balance falls by almost nothing — that's what "minimum payments barely move it" means, in numbers instead of a saying.
The formula
There's no closed-form shortcut here the way there is for a fixed-term loan, because you're solving for time, not payment. The honest way to find it is the same loop a spreadsheet runs: each month, balance = balance × (1 + monthly rate) − payment, where monthly rate = APR ÷ 100 ÷ 12, repeated until the balance hits zero. Count the months, and sum the payments to see total interest.
A real example
Take a $5,000 balance at 22% APR — a realistic rate for an average card today. Monthly rate: 22 ÷ 100 ÷ 12 ≈ 0.018333, or about 1.83% a month.
- Paying $150 a month: the balance clears in 52 months (about 4 years 4 months). Total paid:
150 × 52 = $7,800. Since you borrowed $5,000, that's $2,800 in interest — 56% of the original balance, paid on top of it. - Paying $300 a month: the balance clears in 21 months (1 year 9 months). Total paid:
300 × 21 = $6,300, so interest is $1,300 — 26% of the balance.
What doubling the payment actually buys
Doubling the payment from $150 to $300 didn't just cut the payoff time in half — it cut it to less than half (52 months to 21, a 2.5× speedup) and cut total interest by more than half ($2,800 to $1,300, a $1,500 saving). It's the same mechanism as extra principal on a mortgage: every dollar above the interest due goes straight to the balance, which stops it from generating interest for every remaining month of its life. The earlier and larger the extra payment, the more months of interest it erases.
Why the payment amount matters more than the sticker APR
At $91.67 a month on this balance, the payment exactly equals the first month's interest (5,000 × 0.018333) — the balance would never fall; it would sit flat. Anything above that threshold makes progress, but "above the threshold" and "fast" are very different amounts, as the $150-versus-$300 comparison shows.
The catch: real minimums shrink as you pay
This model assumes a fixed dollar payment every month. Real credit card minimum payments are usually the greater of a small percentage of the balance (often 2%) or a flat floor like $25 — so the required minimum shrinks along with the balance. Modeled that way, the same $5,000 balance at 22% APR takes roughly 968 months — about 80 years — to clear on minimums alone, because the payment keeps shrinking just as fast as the balance does. Issuer formulas vary, so treat that figure as illustrative, but the shape of it is real: a percentage-based minimum is a moving target that a fixed extra payment escapes.
Run your own numbers
The free Debt Payoff calculator runs this month-by-month loop for your real balance, rate and payment — entirely on your device — and tells you straight away if your payment is too small to ever make progress.