Debt avalanche pays the highest interest rate first. Debt snowball pays the smallest balance first. Avalanche minimises interest; snowball maximises momentum. The maths favours one, the psychology often favours the other, and the difference is smaller than the arguments suggest.
How both methods work
- List every debt with its balance, interest rate and minimum payment.
- Pay the minimum on everything.
- Put every spare dollar toward one target debt.
- When it is cleared, roll that payment into the next target.
The only difference is which debt you attack first. Avalanche sorts by rate, descending. Snowball sorts by balance, ascending.
A worked example
Three debts, $300 a month of extra money:
| Debt | Balance | Rate | Minimum |
|---|---|---|---|
| Card A | $4,000 | 22% | $100 |
| Card B | $1,500 | 18% | $60 |
| Loan C | $8,000 | 7% | $200 |
Running the numbers on the same starting point:
- Avalanche: Card A first, then B, then C. Debt-free in about 26 months, paying roughly $1,490 in interest.
- Snowball: Card B first, then A, then C. Debt-free in about 27 months, paying roughly $1,610 in interest.
The avalanche saves about $120 and one month. Real, but not transformative — because the two highest rates sat on the two smallest balances, so both methods attacked similar targets.
When the gap gets bigger
The avalanche’s advantage grows when one debt carries a much higher rate than the rest — a 29% store card alongside a 5% car loan, for example. Every month you delay paying the expensive balance costs real money.
The snowball’s advantage grows when your motivation is fragile: several small balances, a history of abandoned plans, or a strong need to see an account hit zero.
Which one should you choose?
- If one rate is more than about 10 points above the others, use the avalanche. The interest saving outweighs the motivational benefit.
- If the rates are close and you have quit before, use the snowball. Finishing beats optimising.
- If you have one debt, the question disappears: pay the minimums and throw everything at it.
- If a balance is small enough to clear this month, clear it. A closed account is a psychological asset.
The step that matters more than either method
Both plans fail without a surplus. Before choosing a strategy:
- Build a small starter buffer, so a flat tyre does not go back on the card.
- Cut recurring costs rather than relying on willpower at checkout.
- Automate the extra payment on payday; the money should never sit in your current account.
- Stop adding new balances. A payoff plan with fresh spending is a treadmill.
When to consider consolidation
A lower-rate personal loan or a balance transfer can beat both methods by changing the interest rate itself. Two cautions:
- Fees. A 3%–5% transfer fee can wipe out several months of interest savings.
- Behaviour. Consolidating cards into a loan frees up the cards. If the balances return, you now have both.
Common mistakes
- Paying extra on every debt equally. Spreading the surplus slows every payoff and gives you nothing to celebrate.
- Ignoring the minimum on non-target debts. A late fee can exceed the interest you saved.
- Choosing the avalanche and quitting in month four. The best plan is the one you finish.
- Forgetting the credit score effect. Lower utilisation helps; see what moves a credit score.
Frequently asked questions
Is the snowball mathematically worse?
Usually, yes — it can cost more interest. But it produces quicker wins, and a finished snowball beats an abandoned avalanche.
Should I invest instead of paying off debt?
Compare rates honestly. Paying a 22% card is a guaranteed 22% return; a diversified portfolio is not. See how to compare rates.
Does paying off a card hurt my credit score?
Closing the account can reduce available credit and shorten your history. Paying the balance down usually helps utilisation. In most cases, pay it off and leave the account open.
Reviewed 22 October 2026. Educational content, not financial advice. See our disclaimer.
