What's the difference between the snowball and avalanche methods?

The snowball method clears the smallest balance first for quick motivating wins, while the avalanche method targets the highest interest rate first to minimise total interest. This tool lets you compare both.

How does the extra payment work?

Each month you pay the minimum on every debt, plus your extra amount on the priority debt. When a debt is cleared, its freed-up payment rolls onto the next debt — that rolling effect is the snowball.

Which method clears debt faster?

The avalanche method usually saves the most interest and finishes slightly sooner because it kills the most expensive debt first. The snowball clears small balances quickly for motivation. Switch the strategy in the tool and compare the total interest for your own numbers.

Why does it say my minimum payment is too small?

If a minimum payment is less than or equal to the monthly interest on that debt, the balance never falls and the debt can never be repaid. Increase the minimum payment above the interest charge and the calculation will run.

Does it account for interest accruing each month?

Yes. Each month the tool adds interest at the debt's monthly APR (annual rate ÷ 12) before applying payments, so the total interest figure reflects real compounding, not a flat estimate.

What happens to a payment after a debt is cleared?

The minimum payment that was freed up rolls onto the next priority debt on top of your extra payment. This rolling, growing payment is the "snowball" effect that accelerates payoff over time.

Is my financial information private?

Yes. Every calculation runs entirely in your browser. None of your balances, rates or payments are uploaded or stored anywhere.

Debt Snowball Calculator

Debt snowball & avalanche calculator

Enter your debts, choose how much extra you can pay each month, and instantly see your debt-free date and the total interest you’ll pay. It is for anyone juggling multiple credit cards, loans or store cards who wants a concrete payoff plan and to know which strategy costs least.

How it works

The calculator runs a month-by-month simulation of every debt:

Each month it adds interest at the monthly rate APR ÷ 12 ÷ 100 to every balance, then applies each debt’s minimum payment.
Any cash left over — your extra payment plus the minimums of already-cleared debts — is thrown at the priority debt.
The priority order depends on the strategy: snowball targets the smallest balance first; avalanche targets the highest interest rate first.
When a debt hits zero, its payment rolls onto the next one, and the loop continues until every debt is clear.

A debt whose minimum payment cannot even cover its monthly interest is flagged, because it would never be repaid.

Example

Three debts with a 150 extra monthly payment, snowball strategy:

Debt	Balance	APR	Min / mo
Credit card	2,500	19.9%	60
Car loan	8,000	6.5%	180
Store card	900	24.9%	30

The snowball clears the 900 store card first, rolls its payment into the credit card, then the car loan — reaching debt-free in roughly 3 years 2 months. Switching to avalanche (store card and credit card first, by rate) finishes in a similar time but pays noticeably less total interest.

Everything runs in your browser, so your balances and rates stay completely private.