❄️ Debt Snowball vs Avalanche Calculator
← Finance & MoneyYou've got more than one debt. Should you clear the smallest balance first, or tackle the highest interest rate? Enter what you owe and what you can afford each month to see both payoff plans side by side.
Results
Two routes to zero
Snowball Smallest balance first
- Debt-free in
- –
- Total interest
- –
- Total repaid
- –
- First debt cleared
- –
Avalanche Highest rate first
- Debt-free in
- –
- Total interest
- –
- Total repaid
- –
- First debt cleared
- –
Where does your repayment go?
The borrowed money is the same in both plans. The difference is how much interest builds up before you reach zero.
The race to debt-free
The chart's numbers, month by month
| Month | Snowball left | Avalanche left |
|---|
Which debt disappears first?
The order each plan actually clears accounts — which can differ from where the extra money is aimed, because minimums keep clearing debts on their own.
Snowball payoffs
Avalanche payoffs
What if you could pay a little more?
This adds to the same monthly budget above, and both plans are worked out again with it.
Estimate only. This uses fixed annual rates, monthly interest at APR ÷ 12 and fixed minimum payments with no new spending, fees or rate changes. Real lenders may calculate interest daily, change minimum payments or charge fees, so actual payoff dates and interest will differ. How does this calculator work?
See every month's numbers
Snowball, month by month
| Month | Debt at start | Interest | Paid | Debt at end |
|---|
Avalanche, month by month
| Month | Debt at start | Interest | Paid | Debt at end |
|---|
Same debts. Two very different game plans.
You can have the same debts, pay the same amount every month and still end up with two different payoff journeys. The difference is simply where the extra money goes.
The snowball starts with the smallest balance. Clearing one account can feel like crossing something off a to-do list: one less minimum payment to think about, one less balance staring back at you, and a little more momentum for the next debt.
The avalanche starts with the highest interest rate. It tackles the debt charging the most for every dollar left outstanding, which can reduce the total interest you pay. The tradeoff is that your first fully paid account might take longer to arrive.
Neither strategy creates extra money out of thin air. Both still pay the minimum on every debt, and both keep your monthly repayment budget working even after one account is cleared. This calculator shows the numbers behind the choice — the cost, the timing and those little milestones along the way.
The best-looking plan on paper is only useful if the payment fits your actual budget. Start with an amount you can manage, then see what the two approaches would do with it.
The surprisingly weird maths of paying off debt
1. A smaller debt can be a much bigger mood booster.
In this calculator's example, the snowball clears a whole account by month 7. Avalanche doesn't clear its first account until month 21 — yet it still pays less total interest. The route that feels fastest early on isn't necessarily the one that costs least.
2. At 24% a year, $100 can rack up about $2 of interest in a month.
That's the simple monthly estimate: $100 × 24% ÷ 12. For $5,000, it's around $100 in just the first month before any repayment. Interest has a talent for making round numbers uncomfortable.
3. Your monthly payment can stay exactly the same while your debt count falls.
When one account disappears, you don't have to spend less on debt. Roll that freed payment into the next balance and the same money has a bigger target. Fewer bills, same attack budget.
4. Snowball and avalanche can occasionally become the same thing.
If your smallest balance also has your highest interest rate — and the remaining debts line up the same way — both methods target the same accounts in the same order. Different names. Identical maths.
5. A tiny 0%-interest balance can wait under avalanche.
Imagine a $200 interest-free debt beside a larger 25% card. Snowball wants the $200 out of the way; avalanche directs spare money to the expensive card. The smallest bill and the most expensive bill are not always the same problem.
Facts 1 and 2 use the example amounts, not the numbers in your own list.
How does this calculator work?
There isn't one single shortcut formula for juggling several debts, because every balance has its own interest rate and minimum payment. Instead, this calculator walks through your repayment plan one month at a time, always using the same total monthly budget for both methods.
First it adds interest to each remaining balance. Then it pays the minimum on every debt. Whatever is left in the monthly budget goes to the next target: smallest starting balance for snowball, or highest annual interest rate for avalanche. When that debt is gone, its unused payment capacity flows straight to the next one.
The recipe for one month
- Add one month's interest to every debt still open: balance × annual rate ÷ 12, rounded to the nearest cent.
- Pay each open debt its entered minimum, capped at what that debt actually owes.
- Whatever is left of the fixed monthly budget goes down the strategy's list, one debt at a time, until the money runs out or the debts do.
- Note any debt that reached zero, then repeat. The month the last balance hits zero is the debt-free month.
The formulas
monthly rate = annual rate ÷ 12
interest this month = balance at the start × monthly rate
monthly budget = every entered minimum + the extra payment
Balances, minimums and interest are held in whole cents throughout, and interest is rounded once a month per debt. Rounding only at the end would let a plan drift by a few cents.
Worked example, first month
Store card: $1,200 at 8%, $50 minimum. Credit card: $5,000 at 24%, $150 minimum. Personal loan: $8,000 at 11%, $200 minimum. Extra payment: $150, so the monthly budget is $550.
Store card: $1,200 × 8% ÷ 12 = $8.00
Credit card: $5,000 × 24% ÷ 12 = $100.00
Personal loan: $8,000 × 11% ÷ 12 = $73.33
Interest added: $181.33
After the three minimums ($400) the same $150 is left for both plans. The snowball sends it to the store card, leaving about $1,008 there. The avalanche sends it to the credit card, leaving about $4,800 there. Both finish month one with $13,831.33 still owed. The gap only opens later, because the two plans leave different amounts sitting at different rates.
What the model assumes
This is a planning model, not a lender statement. It assumes constant annual interest rates, monthly interest charged before each month's payments, fixed minimums, a fixed total monthly payment budget, no new borrowing and no account fees, penalties or promotional rates. Some cards work out interest daily or recalculate minimum repayments as the balance falls. Some loans limit extra repayments or charge early-payment fees. Use your own statements and agreements for the figures that apply to you.
About minimums. This version uses the fixed monthly minimum you enter for each debt, not a card issuer's real percentage-of-balance rule. Credit card companies rarely calculate minimums as a flat amount — if you want to model a percentage-based minimum on one card, the credit card payoff calculator is the better fit.
If you can't cover the minimums, the calculator stops being the right tool for the moment. In Australia, Moneysmart's debt help page explains hardship options and free financial counselling. Priority bills and contractual minimums come before extra repayments.
Where these ideas come from
The two strategies are described by the Consumer Financial Protection Bureau and by ASIC Moneysmart. Those pages explain the approaches; the arithmetic on this page is this calculator's own, and it has been checked against fixed example cases.
Frequently asked questions
What's the difference between debt snowball and debt avalanche?
Snowball targets your smallest starting balance with any money left after minimum payments. Avalanche targets the debt with the highest annual interest rate. Both keep paying at least the entered minimum on every active account and roll freed payment money into the next debt. Snowball can give you a first account cleared sooner; avalanche generally lowers interest cost under the same assumptions.
Does debt avalanche always save more interest?
With constant rates, the same monthly budget and no special fees or lender rules, directing spare payments to the highest-rate debt is usually the lowest-interest approach. But the difference may be zero — for example, if both methods choose the same order, or all rates are the same. Real-world rates, balance transfers, fees and repayment restrictions can change the comparison.
Is snowball better if I need motivation?
It might be. Seeing an entire account disappear can make a repayment plan feel more manageable. Some people prefer the simpler milestone of "one debt gone" over a smaller total-interest figure. Others prefer to minimise interest. This calculator shows both so you can judge what fits your situation without pretending one choice suits everyone.
Why do I still pay the minimum on the other debts?
Both methods are about where extra money goes, not about skipping bills. Minimum repayments remain part of the model for every debt while it is active. Falling behind can cause fees and other consequences that this calculator doesn't estimate.
What happens to a payment when a debt is paid off?
It stays in your overall monthly debt budget. If one account only needs $30 to finish instead of its usual $50, the other $20 goes toward the next debt in that same month. In later months, the freed $50 is available for the remaining balances, assuming you keep paying the same overall amount.
Why is my payoff date only an estimate?
The calculation uses monthly interest at APR ÷ 12 and fixed minimum amounts. Your card or lender may use daily interest, change required minimums, charge fees or vary the rate. Also, new card spending and changes in what you pay will move your date. Treat this as a way to compare strategies, not a promise from your lender.
What if my monthly budget isn't enough to pay everything off?
The calculator will warn you if it can't project a payoff within its 50-year horizon. Some debts may even grow if their interest exceeds what they receive. Check the inputs and look at what you can realistically afford; if you're struggling to cover payments, speak with your lenders or a free financial counsellor rather than relying on a long-range estimate.
Can I use this for credit cards, personal loans or 0% debts?
Yes, for a simplified comparison, as long as you have a current balance, annual rate and monthly minimum for each account. A 0% debt is fine. But promotional rates that expire, variable-rate loans, daily interest, balloon repayments, early-payment fees and percentage-based card minimums aren't separately modelled here. Use the relevant single-loan or card calculator where you need those details.
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