Add every debt, set one extra payment, and see the snowball and avalanche methods side by side — which clears your debt sooner and which saves the most interest. A verdict, not just a number.
This debt payoff calculator takes the tangle of credit cards, store cards, and loans you're juggling and turns it into a single clear plan. List every debt with its balance, interest rate (APR), and minimum payment, then enter the one extra amount you can afford each month on top of those minimums. The calculator instantly runs two proven payoff strategies — the debt snowball and the debt avalanche — side by side, and tells you which one clears your debt sooner and which one saves you the most interest. Everything updates as you type, so you can add a debt or bump the extra payment by $50 and watch the numbers move in real time.
Most online tools give you one number for one method. This one does the comparison the others skip: it simulates month by month how each strategy attacks your debts and then delivers a plain-English verdict on the trade-off — the exact dollars the avalanche saves versus the motivation the snowball gives. That's the decision people actually need to make.
Both methods pay the minimum on every debt, then throw all of your spare cash at one target debt until it's gone — then roll that freed-up payment onto the next. The only difference is which debt you target first.
The catch: the avalanche is cheaper, but if your highest-rate debt also has a big balance, you might go months before clearing your first debt — and some people lose steam without an early win. The snowball trades a little extra interest for momentum. This calculator shows you exactly how much that trade costs, so it's a real decision rather than a guess.
Because the freed-up payments compound your progress, the last debts disappear far faster than the first. That rollover is the engine behind both methods, and it's why paying a fixed total every month — instead of letting minimums shrink — clears debt years sooner.
| Extra per month | Avalanche payoff | Total interest |
|---|---|---|
| $0 (minimums only) | ~78 months | ~$8,400 |
| $150 | ~42 months | ~$4,200 |
| $300 | ~32 months | ~$2,985 |
| $500 | ~25 months | ~$2,150 |
| $800 | ~19 months | ~$1,500 |
Illustrative figures for the three-debt example above. Every extra dollar attacks principal directly, so even small increases cut years and thousands of dollars.
Pay a fixed total, not the shrinking minimum. Minimums fall as balances drop, which quietly stretches your payoff for years; lock in a fixed monthly amount instead. Stop adding new debt while you pay down — charging more to a card you're trying to clear cancels your progress. Use the rollover. When one debt is gone, add its old payment to the next target rather than absorbing it into spending; this is what makes both methods accelerate. Consider a balance transfer or consolidation loan to cut a high APR, but mind the transfer fee (usually 3–5%) and have a plan to clear it before any promo rate ends. Throw windfalls at the target debt — tax refunds, bonuses, and side income shorten the timeline dramatically. And pick the method you'll stick with: the best payoff plan is the one you actually finish, so if the snowball's quick wins keep you going, the small extra interest can be money well spent.
Both pay minimums on every debt and throw all spare money at one target debt until it is gone, then roll that payment to the next. The snowball targets the smallest balance first for quick motivational wins; the avalanche targets the highest interest rate first to pay the least total interest. The avalanche is mathematically cheaper; the snowball is often easier to stick with.
If saving the most money matters most, choose the avalanche — it always pays the least interest. If you need early wins to stay motivated, the snowball clears individual debts faster. Use the calculator to see exactly how much extra the snowball costs you; if the gap is small, pick whichever you will actually finish.
Dramatically. Because every extra dollar reduces principal and then frees up future payments, even $50–$100 a month can cut a payoff timeline by years and save thousands in interest. Increase the extra payment field and watch the payoff time and interest drop in real time.
Yes. It simulates each month: it adds interest to every balance at the monthly rate (APR divided by 12), applies the minimum payments, then directs all remaining money to the target debt. When a debt is paid off, its payment rolls into the next, just like a real snowball or avalanche plan.
If the total you can pay does not exceed the interest charged each month, the balance never reaches zero. The calculator detects this and warns you, so you know you need a larger extra payment or a lower interest rate (for example through a balance transfer) to make progress.
You can include any debt with a balance, APR, and minimum payment. Many people focus first on high-interest consumer debt like credit cards and personal loans, and treat low-rate mortgages or subsidised student loans separately. Add or remove debts to compare strategies for whichever debts you want to attack.