Finance & Investing

Debt Avalanche vs Snowball Calculator

Compare the two payoff strategies side by side, dollar for dollar.

Two strategies dominate personal-finance debt payoff: the avalanche (highest interest rate first) and the snowball (smallest balance first). The avalanche is mathematically optimal — it saves the most money. The snowball is psychologically sticky — it produces early wins that keep people on track. This calculator runs both on your actual debts and shows you the dollar difference, so you can make an informed trade-off.

Your debts

List every debt: credit cards, student loans, car loans, medical bills. Include balance, minimum payment, and interest rate.

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Avalanche saves more
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Enter your debts to compare avalanche vs snowball.

Note: All calculations run in your browser. Nothing is sent to a server, stored, or tracked.

How this calculator works

The math, in plain English

Both strategies pay the same total monthly amount — the difference is which debt gets the extra payment. The avalanche puts all extra cash toward the highest-interest debt first, minimizing total interest. The snowball puts all extra cash toward the smallest-balance debt first, maximizing the number of "debt eliminated" milestones.

How the simulation works

Each month: (1) add interest to every balance at its monthly rate; (2) pay the minimum on every debt; (3) direct any extra cash to the target debt (highest rate for avalanche, smallest balance for snowball); (4) when a debt hits zero, redirect its minimum plus the extra to the next target. Repeat until all debts are zero.

When snowball beats avalanche
If two debts have very different balances but very similar rates (say, a $500 balance at 19.9% and a $5,000 balance at 20.0%), the snowball may save almost as much money as the avalanche while delivering a psychological win much sooner. The dollar difference in that case is tiny — pick the strategy that keeps you motivated.

The psychology is real

A 2016 Northwestern University study found that snowball users were 14% more likely to actually eliminate their debt than avalanche users, even though avalanche is mathematically superior. The reason: humans are not spreadsheets. Early wins sustain motivation. If your interest rates are similar (within 2-3 percentage points), choose snowball. If one debt has a dramatically higher rate (like a 24% credit card versus a 6% student loan), choose avalanche — the math difference is too large to ignore.

FAQ

Common questions

Which strategy should I actually use?
Use avalanche if your highest-rate debt is also reasonably sized and you have the discipline to stick with it. Use snowball if you have several small debts that can be knocked out quickly for psychological momentum, or if you have struggled to stay motivated with debt payoff in the past. The dollar difference between the two is usually smaller than people think.
What if my extra payment varies month to month?
Use your average extra payment for the calculation. The strategies work the same way with variable payments — just commit to putting whatever extra you have toward the target debt each month.
Should I include my mortgage?
Generally no. Mortgages have low rates (3-7%) and long horizons; including them dilutes the impact of paying off high-interest debt. Focus on credit cards, personal loans, and other debts above ~7% interest. Use our Mortgage Payoff Calculator separately for the house.
What about balance transfer cards or consolidation loans?
These can dramatically reduce your effective interest rate and should be considered if your credit score allows. A 0% balance transfer for 18 months is effectively an interest-free loan — the avalanche savings multiply. Just watch for transfer fees (typically 3-5%) and have a plan for when the 0% period ends.
How do I handle debts with 0% promotional rates?
Include them with their promotional rate, but flag them with their post-promotional rate. When the promo ends, the rate often jumps to 22%+. Plan to pay these off before the promo expires, even if avalanche math would otherwise direct extra cash elsewhere.
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Disclaimer: This calculator is provided for educational and informational purposes only. It does not constitute financial, tax, legal, medical, or professional advice. Results depend on the accuracy of the inputs you provide and the assumptions documented above. Always consult a qualified professional before making decisions based on these calculations.