How to use the debt payoff calculator
- List each credit card or loan with its current balance, APR and minimum monthly payment. Your statement shows all three.
- Use “Add a debt” for more rows, or remove any you do not need.
- Enter the extra money you can put toward debt each month, on top of the minimums.
- Compare the two result cards. Each shows your debt-free date, total interest and the order in which debts disappear.
- Check the chart to see how fast total debt falls under each plan versus paying minimums only.
How the payoff simulation works
The calculator does not use a single formula, because payments move between debts as each one is cleared. It steps through every month instead:
Card issuers usually charge interest daily on the average balance, so a statement can differ by a few dollars from this monthly model.
Worked example
Three debts: a Visa card with $6,500 at 24.99% ($160 minimum), a store card with $900 at 19.9% ($35 minimum) and a personal loan of $3,800 at 11.5% ($120 minimum). With $250 extra, the monthly budget is $565.
Avalanche attacks the Visa first. You are debt-free in 24 months and pay $2,320.46 in interest. Snowball clears the store card in month 4 and the loan in month 13, then finishes in 25 months with $2,859.23 of interest. Paying only the minimums would take 91 months and cost $9,056.90.
Which method should you choose?
Mathematically, the avalanche always costs the same or less, because every extra dollar goes where interest is highest. In the example it saves $538.77. The snowball gives a quick early win: the first debt is gone in four months instead of twenty. If motivation is what keeps you on track, that can be worth the extra cost. The gap is small when your APRs are close together and large when one card charges far more than the rest.
Key features
- Any number of debts, each with its own APR and minimum.
- Avalanche, snowball and minimum-only results side by side.
- Exact payoff month for every debt and a calendar debt-free date.
- Warns you when a minimum payment does not cover the monthly interest.
Practical use cases
Balance transfer planning. In the US and UK, a 0% balance transfer card can pause interest for 12 to 24 months, usually for a fee of 3% to 5%. Enter the transferred balance at 0% plus the fee to see if you can clear it before the promotional rate ends.
Choosing what to pay first. If a lump sum such as a tax refund arrives, run the calculator with and without it on each debt to see which one saves the most interest.
Canada and the UK. Many card issuers set the minimum at a small percentage of the balance plus interest, which shrinks as you pay down the card. Using your current minimum as a fixed amount, as this tool does, gets you out of debt faster than the issuer’s shrinking minimum would.