Debt calculators
What a balance costs to carry, and how long it takes to clear.
Carrying a balance costs money in a way that is easy to underestimate, because the figure that matters is never the one printed on the statement. The minimum payment is a percentage of a falling balance, so it falls too, and the amount actually reducing what you owe shrinks every month while the interest rate has not moved at all. These three calculators take the balance, the rate and the payment you can make, and work the arithmetic through to the month it clears.
3 calculators
- Credit card payoff How long a balance takes to clear, and the interest it costs.
- Debt snowball Several debts at once. Snowball and avalanche, side by side.
- Minimum payment What paying only the minimum costs, under both issuer formulas.
What every debt calculator here assumes
These apply across the cluster. Each page repeats the ones that bear on its own result, so you never have to come back here to read a figure.
- Interest is added before the payment
- Each month adds interest to the balance, then subtracts the payment. That is the order every US issuer uses, and it is why paying a balance in full still incurs one final month of interest.
- The monthly rate is the APR divided by twelve
- A 22.9% APR becomes 1.90833% a month. Because that division ignores compounding, the effective annual cost of carrying a balance is slightly higher than the APR printed on your statement.
- Cents round as they are posted
- Interest rounds to whole cents at the moment it is applied, exactly as an issuer posts it, so the rows of a schedule add up to the total above them.
- Minimums default to 1% plus interest, with a $35 floor
- Issuers use two different shapes and almost none of them say which. Both are modelled, and the assumption is printed next to every result.
What they deliberately leave out
Every exclusion here is a real cost or a real rule. They are left out because including them would need information this site does not have, and a figure built on a guess is worth less than a figure with a stated gap.
- Fees. Late fees, annual fees, balance transfer fees and cash advance fees are real money, and none of them are interest.
- Promotional and penalty rates. A 0% introductory period, or a penalty APR triggered by a missed payment, changes the arithmetic sharply.
- New spending. Every figure assumes nothing further goes on the card.
- Multiple APRs on one card. Purchases, transfers and cash advances often carry different rates, with their own payment allocation rules.