Comprehensive Guide
Learn more in our Personal Finance Guide.
How it works
debt snowball vs avalanche calculator takes your inputs and produces payoff time, total interest, debts. Compare the debt snowball and avalanche methods on your real debts with an extra payment, and see which order finishes faster. You provide 11 inputs: Repayment strategy — choose from Avalanche — highest APR first, Snowball — smallest balance first (default: "avalanche"); Extra payment per month (currency, in dollars) (default: 200 dollars); Debt 1 name (text) (default: "Credit Card"); Debt 1 balance (currency, in dollars) (default: 5000 dollars); Debt 1 APR (percent, in percent) (default: 22 percent); Debt 2 name (text) (default: "Student Loan"); Debt 2 balance (currency, in dollars) (default: 15000 dollars); Debt 2 APR (percent, in percent) (default: 6 percent); Debt 3 name (text) (default: "Car Loan"); Debt 3 balance (currency, in dollars) (default: 8000 dollars); Debt 3 APR (percent, in percent) (default: 8 percent). The calculator returns 3 outputs: Payoff time (the primary result); Total interest (a secondary output); Debts (a supplementary figure). Personal finance decisions trade off today's comfort against tomorrow's security. The numbers behind that trade-off — how much to save, spend, borrow, or insure — are what this calculator makes concrete. Rather than rules of thumb, it gives you the actual arithmetic for your situation so you can compare options side by side and decide with confidence. The underlying formula: Each month: interest = balance x APR/12, payment = minimum + extra to the target debt; freed payments roll forward With the default values, payoff time is computed from the interaction of every input field — change any one of them and the result updates immediately, so you can stress-test different scenarios without re-entering the whole form. Adjust the inputs to match your real financial situation. The defaults are realistic starting points, but every person's circumstances differ — your actual income, expenses, rates, and timelines will produce a different answer. Use the tool iteratively: start with the defaults, then change one variable at a time to see which factor has the largest impact on your outcome.Formula
Each month: interest = balance x APR/12, payment = minimum + extra to the target debt; freed payments roll forward
Tips
- List every debt — including the furniture you put on a card — or the comparison is fiction.
- Keep paying minimums on every account; the extra money targets one debt at a time.
- Automate the extra payment for the day after payday.
- If two debts are close in rate, avalanche by balance first for a psychological win.
Frequently asked questions
Which wins: snowball or avalanche?
Avalanche always costs less interest because it retires the most expensive debt first. Snowball finishes on average a little slower but gives quicker wins. The difference is typically a few hundred dollars on a typical card stack — far less than the cost of giving up halfway, so pick the one you can sustain.
How much extra do I need for the snowball to work?
Any amount above minimums works, even $25. The method needs a target debt, a clear order, and the discipline to roll each freed minimum payment into the next debt. The engine simulates your exact extra amount.
Do I keep paying extra when the last debt is gone?
Yes — chain that same monthly amount into savings or investments. That is how people go from debt-free to investing hundreds per month without feeling it: the habit, not the motivation, carried them.
What should my minimum payment be for the simulation?
Typical cards require around 2% of the balance, and the engine applies that floor. If your lender requires a different minimum, treat the simulation as a close estimate and check the payoff month against your statement.