Debt payoff calculator: snowball vs. avalanche

Enter each debt's balance, APR and minimum payment, then add what you can pay on top. The calculator shows the month you would be debt-free and the interest you would pay under the avalanche method, the snowball method and minimum payments alone. It runs in your browser. Nothing you type is sent anywhere.

How the calculator works

Every month it adds one month of interest to each balance (APR divided by 12), pays every minimum, then sends your extra money to one focus debt. Avalanche focuses on the highest APR. Snowball focuses on the smallest balance. When a debt is paid off, its minimum rolls into the extra for the following months, so your total monthly payment stays the same until the last debt is gone.

The "minimums only" row pays each fixed minimum and nothing more, with no rollover. It is there to show what the extra payment and the rollover are worth.

• Rates and minimum payments are treated as fixed, with no new charges, fees or promotional rates.
• If a payment never covers the interest, the calculator stops at 60 years and tells you.
• Results are estimates for planning, not financial advice. Your statements are the final word.

Worked example: $8,600 across three debts

The calculator opens with a sample: a $600 store card at 18% APR with a $30 minimum, a $3,000 credit card at 26% with a $90 minimum, and a $5,000 personal loan at 12% with a $160 minimum. The minimums total $280. The sample adds $100, for a $380 monthly budget.

Both methods finish in 28 months here, and avalanche saves $54 in interest. The bigger difference is against minimums alone: the extra $100 and the rollover take 32 months off the plan and cut the interest roughly in half.

Avalanche or snowball?

Avalanche never costs more interest than snowball on the same budget. Snowball closes the first account sooner. If the two dates are close, pick the one you will stick with. The longer comparison is in snowball vs. avalanche: which debt goes first?, and how to make a debt payoff plan covers gathering the numbers from your statements.

Questions

Is this debt payoff calculator free?

Yes. It is free, it has no signup, and the math runs in your browser. The balances you type are not sent anywhere or saved.

What is the debt avalanche method?

With the avalanche method you pay every minimum, then send all of your extra money to the debt with the highest APR. When it is gone, its payment moves to the next highest rate. On the same monthly budget, avalanche pays the least interest.

What is the debt snowball method?

With the snowball method you pay every minimum, then send all of your extra money to the debt with the smallest balance. It can cost a little more interest than avalanche, but you close your first account sooner, which helps some people keep going.

Why does paying only the minimums take so long?

Most of a minimum payment on a high-rate card goes to interest, so the balance barely moves. In the example on this page, minimums alone take 60 months and cost $3,522 in interest. Adding $100 a month and rolling finished payments forward cuts that to 28 months.

Does it work for car loans, student loans and medical bills?

Yes. Any debt with a balance, a rate and a monthly payment works. Use 0 for the APR on interest-free debts such as many medical payment plans.

How accurate is the payoff date?

It is an estimate. The calculator compounds interest monthly and assumes fixed rates, fixed minimums and no new charges or fees. Real card minimums usually fall as the balance falls, and lenders calculate interest daily. Your statements are the final word.

Keep the plan on your iPhone

Debtless is a free app that runs this same month-by-month math and keeps it up to date as you log payments. It adds Cash Flow and Custom payoff orders and statement scanning. No account, no bank linking, no ads, no subscription.