Roll-Down Your Credit Card Debt Calculator!
The roll-down (avalanche) method targets your highest interest rate first to save the most money, then rolls each cleared payment onto the next-costliest debt.
A worked example
Running this tool on current national benchmarks (Federal Reserve / Freddie Mac via FRED (St. Louis Fed)) — swap in your own numbers to see how the result moves.
- Debt 1 — balance
- $9,000
- Debt 1 — rate
- 22%
- Debt 1 — minimum payment
- $180
- Debt 2 — balance
- $4,000
- Debt 2 — rate
- 15%
- Debt 2 — minimum payment
- $90
- Debt 3 — balance
- $6,000
- Debt 3 — rate
- 8%
- Debt 3 — minimum payment
- $110
- Extra monthly payment
- $200
43 months · $5,519 total interest
- Total debt$19,000
- Total interest$5,519
- Interest saved vs minimums$9,574
The math behind it
The roll-down is the avalanche method. Each month every card is charged interest at its own APR and paid its minimum; then all remaining budget — your extra plus any freed-up payments — is thrown at the card with the highest interest rate. When that card is cleared, its payment rolls down onto the next-highest-rate card, and the total hitting your target keeps growing. Because the most expensive debt dies first, this ordering pays the least interest overall.
Assumptions & limits
- Debts are targeted highest-rate-first, regardless of balance size.
- Each card's APR is fixed for the whole payoff.
- All minimums are paid every month, plus the extra amount.
- No new purchases are added to the balances during payoff.
- Each cleared payment rolls down onto the next-highest-rate debt.
Common questions
Why target the highest rate instead of the smallest balance?
Interest is the cost of carrying debt, and the highest-APR card costs you the most per dollar. Killing it first stops the most expensive bleeding, so you pay less interest in total and usually finish a bit sooner than the snowball. The trade-off is that a high-rate card can also be a large balance, so the first win may take longer to feel.
How much can the roll-down save over paying minimums?
It depends on your balances, rates, and extra payment, but on high-APR credit cards the difference is often thousands of dollars and years of payments — the calculator shows both figures for your exact numbers. The saving comes entirely from directing extra dollars to the costliest debt and rolling each freed payment forward.
Is the roll-down the same as the avalanche method?
Yes. "Roll-down" and "avalanche" are two names for the same approach: pay minimums everywhere, attack the highest interest rate first, then roll each cleared payment down to the next-costliest debt.