Debt Payoff Calculator — Avalanche vs Snowball: When Will You Be Debt-Free?

Both plans obey the same monthly rules; only the target of the spare money changes. Each month, every debt is charged interest on its opening balance (balance × APR ÷ 1200) and paid its minimum — that month’s interest plus 1% of the opening balance, with a $25 floor, never more than the balance plus interest — unless you enter a fixed minimum on a debt, in which case that amount is used for it. Whatever budget remains after all minimums are paid goes to one target debt: the highest APR under the avalanche, the smallest balance under the snowball. If the target clears mid-month, the leftover cascades to the next target in the same month. Balances are carried exactly — nothing is rounded until the final numbers are displayed.

The Advanced options bend those rules in two declared ways. A per-year extra and a one-time extra land on the target debt in their month, on top of the budget, in both plans alike. And if you let the total shrink instead of keeping it fixed, the spare amount above the minimums stays where it started while the monthly total falls as each debt’s minimum disappears — the comparison above prices both behaviours on your own debts.

A debt payoff plan is a rule for aiming money you were already going to pay. It has exactly three moving parts. First, every debt gets its minimum payment, every month, so nothing falls behind. Second, whatever is left of your monthly budget becomes one extra payment, aimed at a single target debt. Third, when that target dies, its whole payment — minimum and extra together — rolls down to the next target. That roll-down is the engine of every plan on this page: the payment aimed at the last debt is far larger than the one aimed at the first, even though the budget never changed.

That is all a debt payoff calculator needs from you: the three inputs are each debt’s balance, its APR, and one monthly budget that covers every minimum with something to spare. Call it a debt repayment calculator or a plain debt calculator and the machinery is identical — what changes between tools is only the order they aim the spare money in, and whether they show you the schedule honestly, payoff loan by loan and month by month, or just print a date. Treat any debt calculator payoff date as a projection built from your numbers, not a promise: it assumes the budget holds, the APRs hold, and no new spending lands on a balance in the plan.

A plan is also different from the two things it is most often confused with. Paying minimums only is not a plan — because card minimums shrink as balances fall, minimums-only stretches a payoff across decades. And paying “a bit extra on everything” is not a plan either: the comparison further down this page shows the same extra $150 saving $665.70 when it is aimed, and only $153.04 when it is spread across the same three debts. The order is not a detail of the plan. The order is the plan.

The debt snowball orders debts by balance, smallest first, and ignores interest rates entirely. This page doubles as a debt snowball calculator — the snowball is one of the two plans it runs on every set of debts — so the worked example below is not a retelling, it is the tool’s own output. Add these three debts above: a credit card, a personal loan and an auto loan, $19,900 in total, on a $700 monthly budget.

The worked set used throughout this guide: $19,900 of debt. Month 1 minimums are $155.96 + $85 + $255 = $495.96, so a $700 budget leaves $204.04 of spare money to aim each month at the start.

The snowball order is Personal Loan ($1,900) → Credit Card ($4,800) → Auto Loan ($13,200). In month 1 the minimums come to $495.96, so the spare $204.04 lands entirely on the personal loan, which receives $289.04 in total and drops to $1,627.57. The card and the auto loan get their minimums and nothing more — that is the discipline of the method, and also its cost, because the card is the most expensive balance on the page and it waits.

It waits seven months. The personal loan clears in month 7, with the card still standing at $4,383.46 — and that moment is the entire argument for the snowball. A whole debt is gone, one fewer minimum is due each month, and the freed $289.04 now rolls onto the card, which clears in month 19; the auto loan, minimums-only for most of the race, is finished off by the combined roll-down in month 33. Total interest: $3,112.60. Used purely as a snowball debt calculator, the tool’s job is that schedule; the method’s job is the streak of early wins that keeps a real household paying month after month.

Many people run the same order away from the screen, tracking wins in a debt snowball spreadsheet or on a paper debt snowball worksheet pinned to the fridge. The tracking works — a crossed-out debt is a powerful thing — but the sheet only records the plan; a snowball calculator is what checks the plan’s arithmetic, including the month a cleared debt’s payment cascades into the next one. Record the streak wherever you like. Compute it here.

In the avalanche method debt is attacked in APR order, dearest first, and balance size counts for nothing. Run the debt avalanche method over the same three debts — the same $19,900, the same $700 budget — and the order flips: Credit Card (26.99%) → Personal Loan (10.49%) → Auto Loan (6.99%). The spare $204.04 in month 1 goes to the card, which receives $360.00 in total, because every dollar removed from a 26.99% balance stops roughly 27 cents a year of future charges, while a dollar on the 6.99% auto loan stops seven.

The card clears in month 17 — and the personal loan, which the snowball killed in month 7, follows just one month later, in month 18, because the card’s freed payment cascades onto it at full size. The auto loan closes the plan in month 33. Total interest: $2,833.69.

Same debts, same $700 monthly budget, computed by the calculator above. The avalanche costs $278.90 less interest; the snowball clears its first whole debt ten months sooner.

Put side by side, the two plans finish in the same month and the avalanche costs $278.90 less — that is what the avalanche method buys on this set: not speed, but price. What the snowball buys is the month-7 win, ten months before the avalanche clears anything at all. Neither purchase is irrational; they are priced differently, and now you can see both prices. The gap widens when rates and balances diverge — a large balance at a high rate is where a debt avalanche earns its name — and shrinks towards nothing when the debts are similar, which is why the honest answer to “which method?” starts with running both.

Extra money is the fuel of both plans, but where it lands matters almost as much as how much there is. Take the worked set — $19,900 across a card, a personal loan and an auto loan — and find an extra $150 a month, three different ways.

The same extra $150 a month on the worked set, aimed two ways. Aimed by the plan it saves $665.70 against the baseline; spread evenly it saves only $153.04 — the aim is worth $512.66.

Aimed by the plan, the $150 simply raises the budget from $700 to $850, and every spare cent follows the avalanche order. The finish line moves from month 33 to month 26 and interest falls by $665.70. Spread evenly — $50 added to each debt, the instinctive “fair” option — the same $850 leaves the account every month, yet the plan takes a month longer and costs $512.66 more in interest, because $50 of it sits on a 6.99% auto loan doing a third of the work it would do on the 26.99% card. Fair is expensive. Aimed wins.

Against a single loan, the question changes shape: this is the early loan payoff calculator question — how much sooner does one loan die, and what does the head start save? Searchers phrase it every way round — early payoff calculator, early loan payoff calculator, loan payoff early calculator — but the sum underneath is the same. The auto loan alone, paid at exactly its $255 payment, runs 62 months and costs $2,555.68 in interest. Add the same $150 and pay $405 a month and it dies in month 37 — 25 months early, with $1,074.59 of interest never charged. For one loan with a fixed schedule that is the whole story, and our Loan Calculator shows that loan’s full month-by-month schedule; inside a multi-debt plan, though, a single loan is rarely where extra money does its best work — the plan comparison above is the proof, since the aimed $150 beats even the spread on the full set while the card’s 26.99% is still standing.

A consolidation loan pays off the debts above in one move and replaces them with a single new loan — one payment, one APR, one fixed end date. The pitch is almost always the payment: stretch the balance over a longer term and the monthly number falls. What the pitch leaves out is the interest. Take this page’s worked set — $19,900 of debts on a $700 budget, where the avalanche charges $2,833.69 of interest over 33 months. Roll those debts into a 12% loan over 48 months instead and the payment drops to $524.04, but the interest climbs to $5,254.08 — $2,420.39 more, and the debt is still alive 15 months after the avalanche finished it. Run a shorter, cheaper loan — 8% over 24 months — and the picture flips: $1,700.55 of interest, $1,133.14 less than the avalanche, debt-free 9 months sooner — at the price of $900.02 a month. Neither answer is the true one in general; each is true for its numbers. Enter the loan you are actually being offered below and read its row against both plans.

Against the cheaper of your two plans (the avalanche): interest $216.22 more · 46 months longer · a monthly payment $676.30 lower.

Three things the table cannot see. A consolidation loan only works if the cleared cards stay at zero — new spending on them rebuilds the old debts alongside the new loan. The loan’s rate is fixed for its term, while a card APR can move. And the comparison holds your plans at the budget and options set above: change those, press Calculate Payoff again, and the loan is re-priced against the new plans. A cheaper row is arithmetic, not a recommendation — whether trading a lower payment for more interest, or a higher payment for less, suits your situation is your call. This is general information, not financial advice.

Half the searches in this corner of the internet are not for a calculator at all — they are for a debt payoff spreadsheet, a debt tracker, something to keep by hand. The instinct is sound: a plan you look at every month outlives a plan you computed once. If you keep a sheet, these are the columns that earn their place.

The six columns a debt payoff spreadsheet actually needs. Everything else is decoration.

A free debt payoff spreadsheet or a simple debt payoff tracker covers the recording half of the job well, and a sheet has two honest advantages: it bends around irregular income, where the extra payment is a different amount every month, and it can carry quirks the tool’s single minimum rule does not model, like a 0% promotional period ending mid-plan. Where sheets quietly fail is the cascade — the month a debt clears, its payment has to jump to the next target in the same month, minimums have to be recomputed as balances shrink, and one dragged formula can flatter the finish date by a year without anyone noticing. That is the half a calculator does better: both orders, recomputed from scratch on every edit, with the interest counted to the cent.

The practical division of labour: use the tool to choose and price the plan, and whatever you like — sheet, app, notebook — as the debt tracker that keeps you honest between calculations. When the numbers change, come back and re-run the plan; a tracker records the past tense of a plan, and the calculator is its future tense.

Your budget does not cover the minimums. A plan is a way of aiming spare money; if there is no spare money — if the minimums alone exceed what you can pay — there is nothing to aim, and no order, however clever, changes the arithmetic. That is the moment to talk to the issuers about hardship arrangements, before missed minimums add fees and penalty APRs that make the hole deeper.

There is no cash buffer at all. A starter emergency fund — even a few hundred dollars, commonly around $1,000 — comes before aggressive payoff, for one practical reason: the next broken appliance or car repair otherwise goes straight onto the card the plan is trying to clear, and the plan restarts. Clear the buffer first, then attack the debts, then build the fund out to three to six months of expenses.

Debts are already in arrears or with collectors. Once payments are being missed, the order of operations changes: fees, penalty rates, charge-offs and your rights in the collection process all matter more than the difference between two payoff orders. Nonprofit credit counselling — in the US, agencies affiliated with the National Foundation for Credit Counseling (NFCC) review a full debt picture for free — exists for exactly this situation. That is information about where help lives, not advice about your debts; this page is a calculator, and its disclaimer below says the same.