Debt Snowball vs. Avalanche: Choose a Plan You Can Keep

General Canadian educational information published by DebtHelp.ca; no personal assessment or licensed-professional review is represented. Our editorial approach.

The useful bits, first

The avalanche targets the highest interest rate; the snowball targets the smallest balance.
Compare both methods with the same total payment and the same assumptions.
If required payments do not fit, changing the order may not solve the underlying gap.

Before choosing an order, check the budget

A repayment method answers a narrow question: where should extra money go after required payments? It does not create that extra money. Start by checking whether your household can cover essential expenses and the required payments on each account. If it cannot, a different ranking of balances may leave the same shortfall.

This comparison assumes accounts are current, rates are known and extra payments are allowed without a penalty. Overdue amounts, secured debt, legal deadlines or a special contractual requirement can change the discussion. Ask for qualified help if any of those issues apply. A tidy method is only helpful when its assumptions match the actual situation.

The avalanche: put the extra toward the highest rate

With an avalanche, you make the required payments on your accounts and direct the available extra amount to the debt with the highest interest rate. When that account is paid off, its payment joins the extra amount going toward the next target. The total repayment budget stays steady where possible.

Under comparable assumptions, directing extra money to a higher rate reduces the interest that balance generates sooner. That is the mathematical reason for the approach. It is not a promise about your actual savings: fees, changing rates, payment timing and new borrowing affect the result. Check whether an advertised promotional rate is about to end before deciding which account is truly most expensive.

The snowball: close the smallest account first

With a snowball, the extra payment goes to the smallest balance while required payments continue on the others. Closing a small account can create a clear milestone and reduce the number of balances you are managing. Some people find that easier to sustain than working on a much larger balance first.

The trade-off is that the smallest balance may not have the highest rate. You may keep a more expensive balance outstanding longer. There is no need to pretend that motivation and interest cost are the same measure. Decide which matters in your situation, and understand the financial trade-off before choosing the method.

A small example using the same extra payment

Consider a hypothetical person with three accounts: $600 at 12%, $2,400 at 24%, and $5,000 at 18%. Their required payments are already covered, and they have another $150 available this month. The snowball directs that extra $150 to the $600 account. The avalanche directs it to the $2,400 account at 24%.

Using a simple annual-rate-divided-by-twelve illustration, an extra $150 principal reduction would lower the next full month’s interest by about $1.50 at 12%, or $3 at 24%. These are illustrative marginal amounts, not a payoff forecast. Actual daily balances and the date the payment arrives change the result. The example holds the extra payment constant so that you can see what the order alone does.

Build a routine that survives an ordinary bad month

Write down the target account and the amount you intend to pay. Review the plan when a rate changes or a bill arrives that you expected only once a year. A small reserve for predictable irregular costs can keep a repair or school expense from undoing several months of repayment work. Choose an amount your circumstances can support.

If you automate payments, make sure the account can cover them when they are processed. Track actual balances, not only a projected end date. If you need to reduce the extra payment temporarily, distinguish that from missing a required payment. A workable plan is allowed to change when the underlying numbers change.

Know when to ask a different question

If you are borrowing again to cover the payments, ask whether repayment on the current terms is realistic. If you are choosing between a minimum payment and essentials, start with qualified help, not a more elaborate spreadsheet. A counsellor or trustee can explain options that a payment-order method does not address.

For a single fixed-rate balance, try our repayment calculator to see how a payment changes the estimate under its stated assumptions. For several accounts, use a consistent model and compare total interest, expected duration and the payment you can keep making. Keep the assumptions beside the answer so the projection remains a planning tool.