Debt Payoff Calculator
List your debts, add anything extra you can pay each month, and compare the Snowball and Avalanche methods side by side.
Your debts
Enter each debt's balance, rate, and minimum payment
On top of all minimums. This is the money that snowballs from one debt to the next.
Snowball vs. Avalanche
Same debts, same budget, two payoff orders
Snowball
Smallest balance first
3 years 5 months
Total interest
$3,381.25
Avalanche
Highest rate first
3 years 5 months
Total interest
$3,055.91
Avalanche saves you
$325.34
in interest. The Snowball's edge is momentum: it clears whole debts faster for quicker wins.
Total you'll pay either way (principal + interest)
$24,055.91 – $24,381.25
Total balance over time
How fast your combined debt drops under each method
Snowball vs. avalanche: which should you use?
How this debt payoff calculator works
The avalanche method targets your highest interest rate first, which mathematically saves you the most money and usually clears the debt soonest. The snowball method targets your smallest balance first, so whole debts disappear quickly, which gives people the wins that keep them going.
Enter each debt's balance, interest rate, and minimum payment, add whatever extra you can put toward debt each month, and this calculator runs both strategies side by side so you can see the real gap in time and interest between them.
Why the math winner is not always the right pick
Avalanche wins on paper almost every time, and for a spreadsheet, that would settle it. People are not spreadsheets. Someone with four debts who picks avalanche might not clear the first one for over a year, and a year with no visible progress is exactly when people get discouraged and quit. Snowball trades some interest savings for a debt gone in month two, which is often the difference between sticking with the plan and giving up on it.
If the interest rates across your debts are close together, the math gap between the two methods is small anyway, and snowball's momentum is close to free. If one card is sitting at 27% while everything else is under 8%, the avalanche's savings get too large to ignore, and that debt should go first regardless of its balance.
The lever that matters more than the method
Whichever method you pick, the extra amount you add each month moves the payoff date more than the choice between snowball and avalanche ever will. Doubling your extra payment usually cuts years off the timeline. Switching methods usually moves it by months. Pick a number you can actually sustain every month, not the largest number that looks good today and gets skipped in March.
What happens when a debt is paid off
Once a debt clears, roll its entire payment, minimum plus whatever extra you were adding, onto the next target instead of letting it drift back into regular spending. That rolling payment is what makes each debt disappear faster than the one before it, and it is the part of the plan most people forget to actually do once the first debt is gone.
How this is calculated
It simulates paying off all your debts month by month under two strategies, so you can compare how long each takes and how much interest each costs.
Each month, interest is added to every balance (balance × APR ÷ 12) and the minimum payment is made on each debt. Whatever is left of your total monthly payment is thrown at one target debt: the smallest balance (Snowball) or the highest interest rate (Avalanche). When a debt is cleared, its freed-up payment rolls onto the next target. The Avalanche always pays the least total interest; the Snowball clears individual debts faster for quicker wins.
What it assumes
- Your total monthly payment must exceed the combined first-month interest, or the balances never shrink.
- APRs and your total monthly payment stay constant.
- No new charges are added to any balance.
Frequently asked questions
What's the difference between the snowball and avalanche methods?
The snowball method pays off your smallest balance first, regardless of interest rate, for quick psychological wins that build momentum. The avalanche method pays off your highest interest rate debt first, which minimizes total interest paid. Avalanche saves more money mathematically; snowball tends to have better real-world follow-through for many people.
Should I pay minimums on everything else while focusing extra payments on one debt?
Yes, that's the core mechanic of both methods: pay the required minimum on every debt to stay current, then direct every extra dollar at the one target debt until it's gone, then roll that entire payment into the next target.
Does this calculator account for changing interest rates?
No, it assumes your current interest rates stay fixed for the payoff period. Variable-rate debt, like many credit cards, can have its rate change, which would shift the actual payoff timeline shown here.
Is it better to pay off debt or invest extra money?
As a rough guide, debt with an interest rate above what you could reliably earn investing (often cited around 6-7%) is usually worth prioritizing paying off first; lower-rate debt leaves more room to split extra money between payoff and investing, depending on your comfort with debt.
Estimates assume fixed interest rates and consistent on-time payments, with no new charges added. Your real payoff depends on your lender's terms. This is not financial advice.