Debt Snowball & Avalanche Calculator
Enter up to four debts and this works out the order to clear them in. Snowball takes the smallest balance first; avalanche takes the priciest. Both are shown so the trade-off is a number.
Debt free in
37months
- Debt free in
- 3 years 1 month
- Total interest
- $4,885.87
- Total balance
- $15,500.00
- 1. Debt 1 clears
- 6 months
- 2. Debt 2 clears
- 1 year 9 months
- 3. Debt 3 clears
- 3 years 1 month
- The other order would cost $335.84 less in interest, though it clears its first debt later.
- Every debt keeps getting its minimum. The extra goes at the target debt, and when one clears its whole payment rolls onto the next — which is where the snowball gets its name.
- Avalanche always costs less on paper. Snowball clears the first balance sooner, and people who see progress tend to keep going.
About the debt payoff calculator
Both methods work the same way and differ only in the order. Every debt gets its minimum payment each month. Whatever you can spare on top goes entirely at one target debt, and when that debt clears its whole payment — minimum plus the extra — rolls onto the next one. That rolling is where the snowball gets its name, and it is what makes the last debts clear so much faster than the first.
Avalanche targets the highest rate first, which always costs less in interest. Snowball targets the smallest balance first, which always clears the first debt sooner. The gap between them is usually smaller than people expect — often a few hundred over several years — which is why the choice is more about temperament than arithmetic.
The honest case for snowball is that a plan you abandon saves nothing. Clearing a balance entirely, and having one fewer payment to make, is a visible result early on, and people who see progress tend to keep going. The honest case for avalanche is that it is simply cheaper, and if the rates differ a lot — a 24% card against a 6% loan — the gap stops being trivial.
What neither method survives is new spending. The whole model assumes the balances only go down. Putting more on a card while paying it off resets the plan and is the main reason payoff schedules fail.
One thing worth doing before either: ask for a lower rate, or move a balance to a promotional rate. A rate cut is a saving you get without finding any more money, and on card debt it is often available for asking.
What it works out
- Up to four debts at once
- Snowball and avalanche compared, in interest and in time
- When each individual balance clears
- What an extra monthly payment does to the whole plan
The formula
Each month: every debt gets its minimum, the spare goes at the target, and a cleared debt’s payment rolls onto the next
There is no single formula for this — it is a month-by-month simulation — but the rule it follows fits in a sentence.
Every debt is charged a month's interest and paid its minimum. Whatever you have spare goes entirely at one debt: the smallest balance under snowball, the highest rate under avalanche. When a debt clears, its minimum is freed up and joins the spare, so the amount attacking the next debt grows every time one falls.
That acceleration is the point. In the example here the first debt clears in six months, the second fifteen months after that, and the third sixteen months after that again — even though the third is by far the largest. By the time it is the target, $565 a month is going at it rather than the $200 you started with.
Which order to choose is the only real decision. Avalanche always costs less in interest, by definition, since it removes the most expensive debt first. Snowball always clears the first balance sooner. The gap in pounds is usually modest, and the plan you actually finish is the one that wins.
- Balance
- What is owed on each debt today.
- Rate
- The annual rate on that debt. Card rates are often far higher than people assume.
- Minimum
- The smallest payment the lender will accept each month.
- Extra
- What you can find on top of all the minimums. This is what does the work.
A worked example
Three debts — $1,200 at 7%, $4,800 at 22% and $9,500 at 18% — cleared smallest balance first, with $200 a month on top of the minimums.
That works out to 37 months.
- Debt free in
- 3 years 1 month
- Total interest
- $4,885.87
- Total balance
- $15,500.00
- 1. Debt 1 clears
- 6 months
- 2. Debt 2 clears
- 1 year 9 months
- 3. Debt 3 clears
- 3 years 1 month
Questions
What is the difference between the snowball and avalanche methods?
The order. Snowball clears the smallest balance first for the momentum; avalanche clears the highest rate first for the money. Everything else — the minimums, the extra payment, the rolling — is identical.
Which one should I use?
Avalanche if the rates differ a lot, since the saving is real. Snowball if you have struggled to stick with a plan before, since clearing a whole debt early is the thing that keeps people going. Run both here — if the difference is small, pick the one you will finish.
How much does avalanche actually save?
Often less than expected. On the three debts here it saves $336 over three years and finishes a month sooner. The gap grows when the rate spread is wide, so a 22% card sitting alongside a 7% loan is where avalanche earns its keep.
What does "rolling the payment" mean?
When a debt clears, you keep paying the same total each month and redirect its minimum to the next debt. Your outgoing never drops until everything is gone, and the amount attacking each successive debt keeps growing.
Should I stop using the cards while I do this?
Yes, or the plan does not hold. Every calculation here assumes the balances only go down. New spending on a card being paid off is the single most common reason these schedules fail.
Is a consolidation loan better than either method?
It can be, if the new rate is genuinely lower and the term is not much longer. A consolidation that halves the payment by doubling the term usually costs more in total, so compare the interest rather than the monthly figure.
Should I pay a small balance off just to have fewer payments?
That is exactly the snowball argument, and it is a reasonable one. Fewer payments means fewer chances to miss one, and a cleared debt is a result you can see. It costs a little more in interest and often buys the persistence to finish.
What if I cannot cover all the minimums?
Then this is the wrong tool and the priority is different. Speak to the lenders before missing a payment — most have hardship arrangements — and a non-profit debt advice service rather than a fee-charging one.