Debt Snowball vs Avalanche Calculator NZ

Compare paying off your smallest debt first with paying off your highest interest debt first, and see when you could be debt free.

Adjust your plan

Move the sliders or enter exact amounts.

Debt 1

Set the balance to 0 to leave it out.

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Debt 2

Set the balance to 0 to leave it out.

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Debt 3

Set the balance to 0 to leave it out.

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Your estimate

Updates instantly as your numbers change.

Avalanche: highest rate first

2 yr 8 mo

About $2,653 in interest.

Snowball: smallest balance first

2 yr 8 mo

About $2,780 in interest.

Interest the avalanche saves

$127

Compared with the snowball for these debts.

How this calculator works

Each month every debt gets its minimum payment. Your extra payment, plus the minimums of debts already cleared, goes to one target debt: the smallest balance for the snowball, or the highest interest rate for the avalanche. Interest is added monthly on the remaining balance.

Important assumptions

  • Interest rates and minimum payments stay the same until each debt is paid off.
  • Interest is charged monthly, and no new borrowing or fees are added.
  • Plans longer than 50 years are shown as not paying off.

These results are general illustrations only and are not financial advice. Actual outcomes can differ.

Turn the estimate into a living plan

Fireball connects spending, savings, investments, property, debt, and KiwiSaver in one private financial independence plan.

Explore Fireball

Common questions

Terms explained

  • Debt snowball

    The debt snowball pays off your smallest debt first while making minimum payments on the rest, then rolls that payment into the next smallest.

  • Debt avalanche

    The debt avalanche pays off the debt with the highest interest rate first while making minimum payments on the rest.

  • Revolving credit

    Revolving credit is a home loan that works like a large overdraft: your pay goes in, spending comes out and interest is charged daily on the balance.

  • Offset mortgage

    An offset mortgage links your savings and everyday accounts to your home loan, so you only pay interest on the loan balance minus those savings.

  • Emergency fund

    An emergency fund is cash set aside for unexpected costs or lost income, often three to six months of essential spending.

  • Net worth

    Net worth is everything you own minus everything you owe.

See the full glossary