Debt Payoff Calculator
It plans a route out of several debts at once and shows exactly what the snowball and avalanche methods cost — in months, and in interest.
Debt free in (avalanche)
2y 6m
Months to clear
30
Total interest
$2,104
Total paid
$17,304
Monthly outlay
$590.00
Snowball interest
$2,223
Avalanche interest
$2,104
| Order cleared | Month | Interest paid |
|---|---|---|
| 1. Credit card | 21 | $1,022 |
| 2. Store card | 22 | $248 |
| 3. Car loan | 30 | $834 |
Interest costs 14% of what you owe today.
What it calculates
It plans a route out of several debts at once and shows exactly what the snowball and avalanche methods cost — in months, and in interest.
Why it matters
The order you clear debts in changes the total cost. Avalanche is always cheaper mathematically; snowball clears individual debts sooner, which many people find easier to stick with.
Who it's for
Anyone juggling multiple cards and loans, and people deciding where an extra $200 a month should go.
Formula
- Minimums
- Paid on every debt every month
- Extra
- Surplus above the minimums
- Snowball
- Target the smallest balance first
- Avalanche
- Target the highest interest rate first
Worked example
$5,000 at 22%, $1,200 at 15% and $9,000 at 6%, with $200 extra a month
- 1Pay every minimum, every month
- 2Snowball sends the extra at the $1,200 balance first
- 3Avalanche sends it at the 22% card first
- 4As each debt clears, its minimum joins the surplus
Avalanche costs less interest; snowball clears the first debt sooner
How the debt payoff calculator works
Every month interest is added to each balance, minimums are paid on everything, and the entire surplus is thrown at one target debt. When a debt clears, its minimum rolls into the surplus — which is what makes either method accelerate, and where the snowball gets its name. Avalanche always wins on interest because it removes the most expensive balance first. The gap between the two is often small, and the method you actually stick with beats the one you abandon.
Every month interest is added to each balance, minimums are paid on everything, and the whole surplus is thrown at a single target. When a debt clears, its minimum rolls into the surplus — which is what makes either method accelerate.
Avalanche always wins on interest because it removes the most expensive balance first. The gap is often small, and the method you actually stick with beats the one you abandon.
Common mistakes
- Spreading a surplus evenly across every debt, which clears none of them faster.
- Paying only minimums, where most of the payment is interest and the balance barely moves.
- Clearing debt while carrying no emergency buffer, so the next surprise goes straight back onto the card.
Tips and best practice
- Check whether a 0% balance transfer beats either method before committing.
- Keep the total payment fixed as debts clear; the freed-up minimum is what creates the acceleration.
- If the interest gap between your debts is small, pick snowball — the motivation is worth more than the few dollars.
Frequently asked questions
What is the difference between the debt snowball and avalanche?
Snowball pays the smallest balance first for quick wins; avalanche pays the highest interest rate first for the lowest total cost. Avalanche is always cheaper, sometimes only slightly.
Which debt payoff method is best?
Avalanche costs the least interest. Snowball produces visible progress sooner, and research on real repayment behavior suggests that motivation matters — the best method is the one you finish.
Why does paying only the minimum take so long?
Minimums are typically set at 1–3% of the balance, most of which covers that month's interest. The principal barely moves, so the debt can run for decades.
Should I save or pay off debt first?
Build a small emergency buffer first, then attack the debt. Without a buffer, the next unexpected bill goes straight back onto the card you just cleared.
Does a balance transfer help?
A 0% transfer can save a lot if you clear the balance inside the promotional window. Factor in the transfer fee, usually 3–5%, and what the rate reverts to.
Related calculators
Methodology & trust
- Formula source
- Month-by-month amortization of multiple revolving and instalment debts.
- Last updated
- 2026-07-28
- Privacy
- Every calculation runs in your browser. No inputs are sent to a server or stored.
- Accessibility
- Keyboard navigable, labeled inputs and WCAG AA color contrast.