Debt Snowball vs Avalanche Calculator

How the Debt Snowball vs Avalanche Calculator works

When you owe money on several accounts at once, the question stops being “how do I pay this off” and becomes “which one do I pay off first?” A payoff strategy answers that. This calculator runs the two best known strategies over your debts and shows what each would cost you. Read snowball vs avalanche for the fuller story behind the numbers.

Both strategies rest on the same foundation: you keep making at least the minimum payment on every debt, every month, and you pour whatever spare money you have on top of one debt at a time. The moment that debt clears, its freed-up payment rolls onto the next in line, so the amount you throw at each debt grows as you go. All that separates the two strategies is the order they pick the next target.

The baseline and the two strategies

The calculator scores your debts three ways. The first is the baseline everything is measured against:

• Minimum paymentsis the “no strategy at all” case: you pay each debt's minimum and no more. It is not quite doing nothing, though — when one debt clears, its freed-up minimum is split evenly across whatever you still owe, because real money does not sit idle once an account is gone. It is still always the slowest and most expensive of the three, since it has no extra payment and no deliberate order behind it; if even that spread-out money cannot outpace the interest, the debts never clear. It is here so you can see what having any plan is worth.
• Snowball sends the spare money at your smallest balance first, regardless of rate. You clear a whole account quickly, which is a real, visible win early on. The appeal is momentum: a debt you have finished with is one you never think about again.
• Avalanche sends the spare money at your highest interest rate first. Because interest is what makes debt expensive, attacking the priciest balance first always costs the least in total and clears everything at least as soon. It is the strategy a spreadsheet would pick.

Calculator Inputs

• Your debts: For each one, its type (credit card or loan), the balance you still owe, its minimum monthly payment and its interest rate. Add as many as you need.
• Extra monthly payment:The money you can put toward your debts on top of every minimum. This is the fuel the strategy directs. Leave it blank if you can only cover the minimums for now; the strategies still differ, because a cleared debt's minimum becomes spare money the moment it clears.

Your total monthly budget is simply your minimums plus that extra, and it stays the same under both strategies. That is the point of the comparison: same money, same debts, only the order changes.

How each month is calculated

Every month the calculator adds that month's interest to each balance, pays every minimum, then aims everything left over at the target debt. When a debt clears, any spare cash left that month cascades straight to the next target. Interest is charged by debt type. An installment loan charges simple interest on the balance, so its monthly rate is the annual rate split into twelve. A credit card compounds daily, which makes its effective monthly rate a touch higher at the same headline APR:

Setting each debt's type correctly matters, because that daily compounding is part of what makes high-rate card debt the natural first target for avalanche.

Understanding Your Results

The table lines up all three approaches on your debt-free date, the first debt you finish, the total interest and the total you would repay. Minimum payments is the anchor column; the snowball and avalanche figures carry a coloured delta against it, so green shows how much each plan saves you over doing nothing. Below the table, the attack-order lists show the sequence each strategy works through your debts.

The chart has two views. Balance traces your total debt falling over time under all three approaches, with the minimum line the one to beat. Payment picks one approach and shows how your monthly budget is split across the debts, so you can watch the money pile onto one debt, then jump to the next the moment it clears. Under minimum payments that same budget shrinks instead of shifting, because the freed-up money is never redirected.

Avalanche always costs the same or less than snowball, so the honest question is rarely “which is cheaper” but “is the saving big enough to matter to you.” When the gap is small, the early win snowball gives you can be worth more than a few dollars of interest, because the strategy you actually stick with is the one that works. When the gap is large, avalanche is the clear call. Either way, both beat paying only the minimums. If your budget cannot cover the interest on your debts, no approach clears them, and the calculator says so rather than showing an impossible date.

Assumptions & Limitations

The calculator holds every rate and minimum payment fixed. In reality card rates are usually variable and their minimums fall as the balance drops, so a real payoff can drift from these figures. It does not model promotional rates, missed payments or fees. Figures are estimates to help you compare strategies, not a guarantee. To see your debts at their current payments, use the debt payoff calculator; to check whether rolling them into one loan would beat both strategies, try the debt consolidation calculator. For why balances have climbed so far, read we owe more than ever, and to protect your score while you pay down, how to get a good credit score.