Add your credit cards, their balances and APRs, and an extra monthly payment to see how much interest the avalanche and snowball strategies each end up costing.
How to Use the Credit Cards Payoff Calculator
Add a row for each card — name, balance, APR, and minimum payment — then set how much extra you can put toward the cards every month beyond the minimums. The calculator runs two full payoff simulations on the same numbers and shows both.
Avalanche sends every spare dollar to whichever card carries the highest interest rate first, then moves to the next-highest once that one clears. Snowball does the same thing but targets the smallest remaining balance instead, regardless of its rate. Both strategies pay every card's minimum every month no matter what — the only difference is where the leftover money goes.
Once a card is paid off entirely, its minimum payment doesn't disappear from the budget — it gets folded into what's available for the next target card, so the total amount going toward debt each month stays constant from the first month to the last.
Avalanche is never mathematically worse than snowball on identical cards; ranking payoff priority by interest rate is, by construction, how you minimize total interest paid. Snowball usually costs a bit more in the end, but it clears entire cards faster in the early months, and for a lot of people that early win is what keeps the plan going — motivation is a real variable here even though it doesn't show up anywhere in the math.
Balance transfers aren't modeled here — moving a balance to a 0% introductory-rate card can beat either strategy shown above, but only for as long as the promotional rate lasts, and only if the transfer fee doesn't eat the savings.