How the debt avalanche works
List every debt with its balance, interest rate, and minimum payment, then add whatever extra you can put toward debt each month. Every debt gets its minimum payment; all the extra goes toward whichever debt has the highest interest rate. Once that debt is gone, its minimum payment rolls into the extra pool too, so the amount attacking the next-highest-rate debt keeps growing — like an avalanche picking up snow as it rolls downhill.
Because every extra dollar targets the debt with the highest interest rate, the avalanche payoff order minimizes total interest paid when the other assumptions are the same. Under the calculator's assumptions, the avalanche payoff order minimizes total interest paid — though as the calculator's comparison line shows, how much it actually saves depends entirely on how spread out your interest rates are.
Avalanche vs. snowball
The snowball method orders debts by balance instead of rate — smallest first, regardless of interest rate. It usually costs a bit more in total interest, but clearing a small debt completely and quickly can be a real motivational win early on. Switch the toggle above to compare both with your own numbers; the comparison note shows the exact dollar and month difference, not a general rule of thumb.
Four debts, $150 extra/month: a 27.49% rewards card, a 19.99% furniture loan, an 11.75% personal loan, and a 6.25% student loan Avalanche: 44 months, $5,367 total interest Snowball: 45 months, $5,594 total interest — avalanche saves $227, one month sooner Reading the payoff order table
Once you calculate, the table below the results shows every debt in the order it actually gets paid off — not necessarily the order you listed them in. Each row shows the debt's original balance, its interest rate, the month it reaches zero, and the total interest paid on that specific debt over its lifetime. The month-by-month schedule underneath goes a level deeper: it shows exactly how much goes to each debt every single month, so you can watch a payment jump the moment an earlier debt disappears.
Frequently asked questions
Should I include 0% balances or a mortgage?
Include 0% balances if you want them represented in the plan. The avalanche gives them the lowest priority for extra payments while any debt with a higher interest rate remains active. If it's a promotional rate with deferred interest, plan to clear it before the promo expires, or the back-interest can land all at once. A mortgage can be included if you want it represented in the same payoff plan, although its size and rate may make it behave very differently from your other debts.
What if two debts have the same interest rate?
The calculator breaks the tie by balance, paying the smaller one first. The interest cost is identical either way at the same rate, so taking the smaller one first frees up that minimum payment sooner and gives you one less bill to track.
Why does a small, 0%-interest debt sometimes get paid off before a higher-priority one?
The avalanche never routes extra money to a low-priority debt while a higher-priority one is still active. A debt with a small balance can sometimes be paid off entirely by its own minimum payment before the calculator ever needs to direct extra money to it. That's not a bug; it just means that debt genuinely didn't need any help to disappear quickly.
What do the advanced options (annual increase, annual payment, one-time payment) do?
Annual increase grows your extra monthly payment by a percentage every year — useful for modeling an increase in the amount you expect to put toward debt. It applies only to the extra payment, not to any debt's minimum payment. Annual Lump-Sum adds a recurring lump sum once a year in the calendar month you choose, such as a bonus or tax refund. One-time payment adds a single lump sum at a specific point in the payoff schedule — the Nth month of the plan, not a calendar month. All three follow the same avalanche or snowball priority order as your regular extra payment.