Debt Avalanche Calculator

Add each debt's balance, APR and minimum payment, plus any extra you can pay monthly. The avalanche method targets the highest interest rate first, which pays the least total interest. See your debt-free date and how much it beats the snowball.

Enter your debts and extra payment, then press Build avalanche plan.

How the avalanche works

The debt avalanche orders your debts from the highest interest rate to the lowest. You pay the minimum on everything and throw all spare cash at the highest-APR debt, because that is where interest piles up fastest. When it clears, its payment rolls onto the next-highest rate.

attack the highest APR first → least total interest

Mathematically this is the cheapest way to pay off multiple debts: every extra dollar kills the most expensive interest first. The calculator accrues interest at APR ÷ 12 monthly, applies minimums, then directs the surplus to the top-rate balance until all are clear.

Worked example

Three debts at 22%, 18% and 9% APR with $150 extra each month:

Target the 22% card first, even if its balance is small - it is the most expensive debt.
Then the 18%, rolling forward each freed minimum plus the extra.
Result: the lowest total interest of any order - the calculator shows it and the snowball gap.

Avalanche vs snowball

The avalanche always pays the least interest and usually finishes a touch sooner. Its downside is psychological: if your highest-rate debt also has a big balance, you may wait a while for the first win. The snowball method clears small balances first for motivation. If you are disciplined, the avalanche saves the most money. Everything is computed in your browser.

Tip: prefer quick wins? Compare with the debt snowball calculator, or check your borrowing ratio with the debt-to-income calculator.

Frequently asked questions

What order does the avalanche use?

Highest interest rate first, regardless of balance. Spare cash attacks the most expensive APR, which minimises the total interest you pay overall.

Is the avalanche really cheapest?

Yes. Directing every extra dollar at the highest rate eliminates the costliest interest first, so no other order pays less total interest - that is a mathematical fact.

Why might I still choose the snowball?

For motivation. If your highest-rate debt has a large balance, the first payoff can feel far away. The snowball's quick early wins help many people stay the course.

Are my numbers sent anywhere?

No. The whole simulation runs locally in your browser. Nothing you enter about your debts is uploaded, logged or stored.

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Mustafa Bilgic · Editor, Calcool
Simulates the avalanche month by month with monthly interest at APR ÷ 12, highest-rate-first ordering and rolled payments. Everything runs in your browser - nothing you enter is uploaded, logged or stored.

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