Debt payoff calculator: snowball vs avalanche
List what you owe, add whatever extra you can pay each month, and see when you'd be debt-free under both methods. You'll also see how much interest each one costs and which debt goes first.
Snowball: pay off the smallest balance first. You get a win quickly, then roll that payment into the next one.
Avalanche: pay off the highest interest rate first. Less satisfying at the start, cheaper overall.
Monthly payment: $700
Avalanche
Highest interest rate first
2 yr 8 mo
Debt-free around June 2029
Interest paid: $2,735
- 1. Store card (month 4)
- 2. Visa (month 17)
- 3. Line of credit (month 22)
- 4. Car loan (month 32)
Snowball
Smallest balance first
2 yr 8 mo
Debt-free around June 2029
Interest paid: $2,976
- 1. Store card (month 4)
- 2. Line of credit (month 13)
- 3. Visa (month 23)
- 4. Car loan (month 32)
Paying only the minimums would take 4 yr 2 mo and cost $5,360 in interest. Your extra $200 a month saves about $2,625.
Which one should you pick?
On paper, avalanche wins. Interest is the only thing that makes debt more expensive, so attacking the highest rate first is the cheapest route. The calculator above will show you exactly how much cheaper with your numbers.
In practice, the gap is often smaller than people expect. When your balances are similar or your rates are close together, snowball and avalanche end up within a few months and a few hundred dollars of each other. In that case the "better" method is the one you'll still be following a year from now. Some people need to see a card hit zero early, and that's a perfectly good reason to choose snowball.
Where avalanche really matters is when you have one large, high-rate balance (a credit card at 25%, say) sitting next to a small low-rate loan. Snowball would have you clear the small loan first while the expensive card keeps growing. If that's your situation, the interest difference above will be big, and it's worth listening to.
Whichever you choose, the two things that move the date most are the extra payment and not adding new balances. A steady extra payment shortens the timeline more than switching methods does.
Questions people ask
Is the snowball or avalanche method better?
Avalanche always costs the same or less in interest, because every extra dollar goes to the most expensive debt first. Snowball usually costs a bit more but clears your first debt sooner, and for a lot of people that early win is what keeps them going. If the interest difference in the results above is small, pick the one you think you'll actually stick with.
What should I put in for extra monthly payment?
Whatever you can reliably add on top of all your minimums every month. A smaller number you can keep paying beats a bigger one you'll drop in March. You can change it later and the timeline updates right away.
Why does the calculator say my debt will never be paid off?
Your total monthly payment isn't covering the interest being added each month, so the balance keeps growing. Raise the extra payment, or check that the minimum payments and interest rates are entered correctly. Credit cards above 20% APR are the usual culprit.
Does this include new purchases on my credit cards?
No. It assumes you stop adding to the balances you list. If you're still using a card, the real payoff date will be later than what you see here.
How is interest calculated?
Each month the calculator adds one twelfth of the APR to each balance, pays every minimum, then sends everything left over to the target debt. When a debt is paid off, its minimum payment rolls into the next one. Real lenders compound a little differently (often daily), so treat the results as a close estimate, not a statement.
This calculator is for planning and education only. It isn't financial advice, and your lender's actual interest and payment rules may differ.
Keep the plan on track
Track the balances as they actually go down
A plan is easy to make and easy to forget. Sumyfi connects your credit cards and loans so you can see each balance drop month by month, alongside your budget and net worth. More on that in the debt snowball tracker guide, or try the net worth calculator to see the bigger picture.