Debt Avalanche Calculator
The debt avalanche method is the cheapest way to pay off several debts: list them by interest rate, highest first, and attack the highest rate while paying the minimum on the rest. Every dollar of extra payment goes where it saves the most interest. The debt payoff calculator above runs the avalanche plan on your debts and compares it with snowball and with minimums only. With the defaults loaded — three debts totalling $15,500 and an extra $200 a month — the avalanche plan clears everything in 32 months with $3,261.54 of interest, finishing in July 2029.
Avalanche beats snowball by $91.00 on the same debts, because it attacks the 22.36% card first instead of the smallest balance. The trade-off is patience: the first debt under avalanche does not clear until month 19, while snowball clears its first debt in month 10. If you can stay disciplined without an early win, avalanche is the right plan. This page shows exactly how the avalanche runs on the default debts.
Your debts — name, balance, APR and minimum monthly payment. Leave unused rows at zero.
How the Debt Avalanche Works
Order your debts by APR, highest first, and ignore the balances. Pay the minimum on every debt, and put all your extra money on the highest-rate debt. When it clears, roll its payment into the next highest-rate debt, and keep rolling until every debt is gone. The logic is simple: a dollar paid against a 22.36% debt saves more interest than a dollar paid against an 11.00% debt, so the highest rate always gets the extra money first. On the defaults, the order is Credit Card A at 22.36%, then Credit Card B at 19.67%, then the personal loan at 11.00%.
The total monthly payment is $600 — $400 of minimums plus $200 extra — and it stays at $600 until the last debt is gone. Card A clears in month 19, Card B in month 23 and the personal loan in month 32. The plan costs $3,261.54 of interest in total, which is $91.00 less than snowball’s $3,352.54 and $3,711.92 less than the $6,973.46 that minimums-only payments would cost. Avalanche always pays less interest than snowball, or the same — never more — because it always attacks the most expensive debt first.
- Order by APR. Highest rate first, whatever the balance.
- Minimums on everything. Every debt gets its minimum payment every month.
- Extra on the target. All spare money goes to the highest-rate open debt.
- Roll the payment forward. When a debt clears, its payment joins the attack on the next debt.
Step 1 — List Your Debts Highest Rate First
Write down every debt with its balance, APR and minimum payment, then sort by APR. The defaults sort as Credit Card A at 22.36%, Credit Card B at 19.67% and the personal loan at 11.00%. The balances do not affect the order in the avalanche method — the rate is the only thing that matters, because the rate is what the interest costs.
Step 2 — Set the Extra Payment
Enter the extra amount you can pay every month. The default is $200, which brings the total to $600 a month. The extra payment is what makes the avalanche move: it all goes to the highest-rate debt, so that debt falls fast even though it is not the smallest.
Step 3 — Watch the Highest Rate Fall
Card A clears in month 19 on the defaults. That is nine months later than snowball’s first win, which is the price of the method. After month 19, Card B gets the rolled-over payment and clears in month 23, and the personal loan gets the full $600 a month until month 32.
Worked Examples: The Avalanche Roll
The table below shows how the avalanche payment grows as debts clear, on the defaults with an extra $200 a month.
| Phase | Target debt | Monthly payment on target | Debt clears in |
|---|---|---|---|
| Months 1–19 | Credit Card A ($5,000 at 22.36%) | $325 ($125 minimum + $200 extra) | Month 19 |
| Months 20–23 | Credit Card B ($2,500 at 19.67%) | $400 ($75 minimum + $325 rolled over) | Month 23 |
| Months 24–32 | Personal loan ($8,000 at 11.00%) | $600 ($200 minimum + $400 rolled over) | Month 32 |
The payment on the target debt grows from $325 to $400 to $600 as debts clear, while the total paid each month never changes. The avalanche finishes in the same 32 months as snowball on these debts, but it costs $91.00 less interest, because the 22.36% card — the most expensive debt — is attacked first and cleared in month 19 instead of month 24.
How to Use the Debt Avalanche Calculator
Enter your debts and the calculator runs the avalanche for you.
- Enter each debt. Name, balance, APR and minimum payment. The calculator takes up to six debts.
- Set the extra payment. The default is $200 a month. Use the quick-set buttons for $50, $100 or $200.
- Read the avalanche row. It shows the months, the total interest, the total paid and the debt-free date.
- Check the avalanche payoff order. The calculator lists each debt with the month it clears.
- Compare with snowball. The snowball row shows what the motivational plan would cost, so you can see the price of the early wins.
What the Calculator Reports
Each figure tells you something about the avalanche plan.
| Figure | What it is | Use it for |
|---|---|---|
| Avalanche payoff order | Debts sorted by APR, highest first | Knowing which debt to attack first |
| Debt-free in | Months until every debt is gone | Comparing plans |
| Total interest | All interest paid over the plan | The cost of the plan |
| Debt-free date | When the last payment is due | Planning the finish line |
| Interest saved vs snowball | Avalanche interest minus snowball interest | The price of the method |
Common Mistakes With the Avalanche Method
Avalanche is mathematically the best plan, but these errors still break it.
- Sorting by balance instead of rate. That is the snowball method. If you sort by balance, you pay more interest.
- Quitting before the first debt clears. The first avalanche win takes 19 months on the defaults. If you need an early win to stay motivated, snowball may suit you better.
- Ignoring small high-rate debts. A small store card at 25% APR is the most expensive debt you have, even if the balance is only a few hundred dollars. It goes first under avalanche.
- Shrinking the payment after a debt clears. The rollover is the engine. Keep the total payment at $600 until every debt is gone.
- Adding new charges. The plan assumes no new charges. A new purchase on a card you are paying off restarts the interest.
Tips for Making the Avalanche Work
Five habits that keep the avalanche moving.
- Automate the extra payment. Set the $200 extra to go out on payday, so willpower is never involved.
- Track the interest, not just the balance. The avalanche wins on interest saved. Watching the interest fall is its own motivation.
- Keep the total payment fixed. The $600 a month stays $600 until every debt is gone.
- Put windfalls on the target. A tax refund or bonus on the highest-rate debt pulls the payoff date closer.
- Switch methods if motivation fades. If 19 months without a win is too long, switch to snowball after the first debt clears. A plan you finish beats a plan you quit.
Debt Avalanche Quick Answers
The avalanche numbers for the default debts, all verified in the calculator above.
| Avalanche plan (3 debts, $15,500, extra $200) | Value |
|---|---|
| First debt cleared | Credit Card A, month 19 |
| Second debt cleared | Credit Card B, month 23 |
| Last debt cleared | Personal loan, month 32 |
| Debt-free in | 32 months, July 2029 |
| Total interest | $3,261.54 |
| Total paid | $18,761.54 |
| Interest saved vs minimums | $3,711.92 and 25 months |
| Interest saved vs snowball | $91.00 |
Related tools on this site: the main debt payoff calculator, the loan payment calculator for a single loan, and the salary calculator to find room for an extra payment. NerdWallet’s credit card payoff calculator is a useful second check on the same numbers.
Frequently Asked Questions
What is the debt avalanche method?
List your debts from highest interest rate to lowest, pay the minimum on all of them, and put every spare dollar on the highest-rate debt. When it clears, roll its payment into the next highest-rate debt. On the defaults, the order is Credit Card A at 22.36%, then Credit Card B at 19.67%, then the personal loan at 11.00%, and everything clears in 32 months.
Is avalanche better than snowball?
Avalanche always costs less interest — $91.00 less on the defaults — because it attacks the most expensive debt first. Snowball gives the first win sooner: month 10 against month 19. If you can stay disciplined without an early win, avalanche is the better plan. If you need early wins, snowball is the better plan for you.
How much interest does avalanche save?
On the defaults, avalanche costs $3,261.54 of interest, against $3,352.54 for snowball and $6,973.46 for minimums only. The saving over snowball is $91.00, and the saving over minimums is $3,711.92. The gap grows when the rates differ more: with an extra $50 a month, avalanche saves $114.52 over snowball on the same debts.
How long does avalanche take on $15,500 of debt?
With $400 of minimums and an extra $200 a month, 32 months, finishing in July 2029. With minimums only, the same debts take 57 months and cost $6,973.46 of interest. The extra $200 a month saves 25 months and $3,711.92 of interest under avalanche.
What if my highest-rate debt is also my biggest?
That is the hardest avalanche case, because the first win takes the longest. On the defaults, the highest-rate debt is the middle balance, so it clears in month 19. If your highest-rate debt is also your largest, consider the snowball method for the first win, then switch to avalanche for the rest.
Disclaimer: This calculator is for general information only and is not financial advice. Results assume fixed minimum payments, monthly compounding on the declining balance, no new charges, no fees and no rate changes. Real cards re-compute minimums monthly and APRs are usually variable. Talk to a qualified adviser before making major debt decisions.