What this credit card payoff calculator does
The credit card payoff calculator answers the two questions every person staring at a card balance asks: "How long will it take to be debt-free at $X a month?" and "If I want to be debt-free in Y months, what do I have to pay each month?" Pick a mode, enter your balance and APR, and watch the answer update live. The yearly timeline below shows how the balance falls and how much interest gets paid along the way.
The math behind the payoff
Credit cards charge interest on the balance, compounded daily in practice but well-approximated by monthly here. Each month:
- Interest charge = remaining balance × (APR ÷ 12 ÷ 100)
- Principal payment = your monthly payment − interest charge
- New balance = old balance − principal payment
Repeat until the balance hits zero. For "target months → payment" mode, the same amortization formula a mortgage uses gives the required payment: M = B × [r(1+r)n] ÷ [(1+r)n − 1], where B is the balance, r is the monthly rate and n is the number of months you want.
Why minimum payments are a trap
Most US card issuers set the minimum at roughly 2-3% of the balance, or $25 — whichever is larger. At 22% APR on a $5,000 balance, the minimum payment is around $100/month, but the interest charge is around $90/month. So $90 of your $100 payment goes to interest and only $10 reduces principal. The balance drops $10 a month, the interest barely budges, and the payoff timeline stretches past 20 years with over $10,000 in total interest. Paying a fixed dollar amount instead of "the minimum" — say $200/month — cuts that to about 32 months and $1,400 in interest. It's the same balance, the same APR, just a different payment behaviour.
Strategies if you have multiple cards
- Debt avalanche. Pay minimums on every card, then put every extra dollar on the card with the highest APR. Mathematically optimal — minimises total interest paid.
- Debt snowball. Pay minimums on every card, then put extras on the smallest balance regardless of rate. Slightly more interest, but the early "I paid one off!" wins keep many people on track psychologically.
- Balance transfer. A 0% APR balance-transfer card can give you 12-21 months of interest-free runway, usually for a 3-5% transfer fee. Worth it if you can pay the balance during the promo period.
The "no new charges" rule
This calculator, like every payoff calculator, assumes no new charges. The single biggest reason people stay stuck in credit-card debt is using the card while paying it down. Park the card, switch to debit or cash for everyday spending, and let the payoff math actually finish.
Use with the rest of the toolkit
For non-revolving loans, the loan calculator and amortization calculator are better fits. For long-term saving on the other side of the ledger, the savings calculator and investment calculator show what compounding does in your favour.