Debt Snowball Calculator
How the Debt Snowball Strategy Works
The snowball method lines your debts up from smallest balance to largest. Each month you make the required minimum payment on every account, but any extra cash is aimed at the smallest balance first. When that balance disappears, the payment you were making rolls to the next debt in line, creating a “snowball” that grows larger with every payoff. The psychological boost of crossing balances off the list can help you stay motivated even if the interest savings are modest.
Snowball vs. Avalanche
This calculator also lets you compare the avalanche method, which targets the highest interest rate first. Avalanche is mathematically optimal because it minimizes interest paid, while snowball emphasizes quick wins. Both approaches follow the same basic amortization math—interest accrues monthly as , payments reduce the balance, and any surplus carries forward. Toggle between methods to see the trade-off between motivation and savings.
Using the Calculator
Provide balances, annual percentage rates, and minimum payments for up to three debts. The optional extra snowball field captures any additional monthly dollars you can devote beyond the minimums. After you choose a payoff method and calculate, the tool simulates month-by-month progress, adds interest before payments, and applies leftover funds to the targeted balance. Results summarize how long it takes to become debt-free, how much interest you’ll pay, and the order in which debts fall.
Worked Example
Imagine three debts: a $1,000 medical bill at 0% interest with a $50 minimum, a $3,200 credit card at 17% with a $90 minimum, and a $7,500 auto loan at 6% with a $220 minimum. If you can add $150 each month to the snowball, the smallest medical debt disappears in two months. Its $50 payment plus the $150 snowball then shifts to the credit card, accelerating progress. Switching to the avalanche method would attack the high-rate credit card first, finishing a few months sooner and saving additional interest.
| Debt | Balance | APR | Minimum |
|---|---|---|---|
| Medical bill | $1,000 | 0% | $50 |
| Credit card | $3,200 | 17% | $90 |
| Auto loan | $7,500 | 6% | $220 |
Experiment with your own numbers to map out payoff dates, compare snowball and avalanche timelines, and see how even a small extra payment shortens the journey.
Tips and Limitations
Real-world lenders may compound interest daily or add late fees, so your statements may differ slightly from the projection. Keep making minimum payments until lenders confirm a balance is zero, and consider automating transfers so the snowball amount grows automatically. Pairing this plan with a budget or emergency fund helps prevent new debt from replacing the balances you just eliminated.