Debt Payoff Calculator
Your debts
Highest APR first — minimizes total interest.
Your payoff plan will appear here
Add a balance, its rate and its minimum payment for each debt above. The plan updates as you type.
Know what this estimate is based on
- Jurisdiction
- United States card and lending practice
- Scope and limitations
- Educational estimate only. Your issuer sets the minimum-payment formula, how a payment is allocated across balances, when interest is charged, and any fees or promotional terms — check your cardholder agreement for the figures that bind.
- Source links checked
- Jul 30, 2026
Built and regression-tested by Smart Tools Lab. It has not been individually reviewed by a licensed financial, tax, or legal professional.
How to use
- 01
Add each debt you owe — a card, a car loan, a student loan — with its balance, its interest rate and its minimum payment.
- 02
Enter the extra amount you can put toward debt each month, on top of every minimum. This is the engine of the whole plan.
- 03
Pick a strategy: avalanche sends the extra to the highest rate, snowball to the smallest balance.
- 04
Read the payoff month and the comparison table, which shows what each strategy costs in months and in interest.
- 05
Follow the payoff order below the results — it tells you which debt gets the extra first, and what to roll it into once that one clears.
Formula
Every debt is paid its minimum every month, without exception — missing one invites late fees and a penalty rate that dwarf anything the ordering saves. Whatever you can pay above the sum of the minimums is the extra, and it all goes to one debt at a time. Avalanche sends it to the highest interest rate, which always costs the least in total. Snowball sends it to the smallest balance, which clears accounts sooner. When a debt clears, its minimum does not return to your budget: it joins the extra and moves to the next target, so the amount attacking your debt grows every time one is retired. That is why payoff accelerates. Each month, every debt accrues balance x APR / 12, its minimum is applied, and the extra plus any freed minimums goes to the current target until it clears.
Example
Three debts and $200 a month above the minimums: - Personal loan: $1,200 at 7.9%, minimum $40 - Credit card: $6,800 at 24.99%, minimum $170 - Car loan: $12,000 at 6.5%, minimum $265 That is $20,000 owed, $475 of minimums, and $675 a month in total. The balance-weighted average rate is 12.87%. Avalanche sends the $200 to the credit card first, because 24.99% is where a dollar cancels the most interest. The card clears in month 24; its $170 minimum then joins the extra, so $370 attacks the personal loan, which clears the very next month. All $675 then goes to the car loan, which clears in month 35. Total interest: $3,465. Snowball sends the $200 to the personal loan first, because $1,200 is the smallest balance. It clears in month 6 — a visible win five months earlier — and its $40 joins the extra. The card clears in month 26, the car in month 36. Total interest: $3,780. So the snowball costs $314 more and finishes one month later, in exchange for clearing an account in month 6 instead of month 25. That is the whole trade, and $314 is what it costs you.
Definitions
- Debt avalanche
- Paying every minimum and sending all spare money to the highest interest rate first. Mathematically the cheapest order.
- Debt snowball
- Paying every minimum and sending all spare money to the smallest balance first. Costs a little more, clears individual debts sooner.
- Extra payment
- What you can pay above the sum of the minimums. The engine of any payoff plan — without it, only the minimums run.
- Rolling payment
- The freed-up minimum from a cleared debt joining the extra and moving to the next target, which is what accelerates the plan.
- Minimum payment
- The least each creditor accepts. Paid on every debt, always, regardless of which one is receiving the extra.
- Payoff order
- The queue your debts are cleared in, decided by the strategy — by rate for avalanche, by balance for snowball.
- Weighted average APR
- Your blended rate across every debt, weighted by balance. The number a consolidation offer has to beat to be worth taking.
- Total interest
- Everything paid above the original balances across the whole plan. The figure the two strategies actually differ on.
- Debt-free date
- The month the last balance reaches zero at your current budget and order.
- Revolving debt
- Credit cards and lines of credit, where the balance and payment move with use. Usually the highest-rate debt in a queue.
- Installment debt
- Auto, personal and student loans with a fixed payment and end date. Their minimums are contractual and cannot be reduced.
- Penalty APR
- The elevated rate a creditor may apply after a late payment — a good reason never to skip a minimum to fund the extra.
Good to know
What the comparison tool actually does
Most debt calculators ask you to commit to one method before you see a result. This tool does the opposite: it takes a single set of debts and a single monthly budget and runs them through two different priority rules at the same time, then lays the outcomes side by side. Nothing about your debts changes between the two runs -- the balances, the rates, the minimums, and the extra payment are all identical. The only difference is which debt the leftover budget targets each month. Because everything else is held constant, the gap you see between the two columns is caused entirely by ordering, which makes it a clean, fair comparison. The headline outputs for each method are the total number of months to become debt free and the total interest paid along the way. Subtracting one column from the other gives you two decision numbers: how much interest one ordering saves over the other, and how many months sooner one finishes. The tool also shows the order in which debts are cleared and the month each one disappears, so you can see not just the final totals but the path each method takes to get there. That path matters as much as the destination, because the early months feel very different under the two rules even when the finish lines are close together.
How the constant-budget engine works
The engine is built on one fixed number: your monthly budget. It is computed once as the sum of every debt's minimum payment plus the extra amount you add, and it stays the same for the entire plan. Each month the engine works in three steps. First, every debt accrues interest equal to its current balance times its APR divided by twelve, so a 24% card adds 2% of its balance that month while a 6% loan adds half a percent. Second, each debt's minimum payment is applied. Third, whatever budget remains after the minimums is poured into a single priority debt until either that debt is gone or the budget for the month runs out; any spillover then moves to the next priority debt. This sequence repeats month after month until every balance reaches zero. The structure is identical for both snowball and avalanche -- the interest accrual, the minimums, and the constant budget never change between them. What changes is only the rule used in the third step to decide which debt is the priority. Understanding this shared engine is the key to reading the comparison correctly: because the machinery is the same, any difference in months or interest is attributable purely to the ordering choice, not to spending more or less money.
How rollover powers every multi-debt plan
The reason a multi-debt plan speeds up over time is rollover, and it is shared by both methods. When a debt is paid off, its minimum payment is no longer owed. But the budget does not shrink -- it was fixed at the start. So the money that used to cover that minimum now has nowhere to go except into the constant budget, where it is redirected to the current priority debt. In effect, every debt you clear hands its monthly payment forward to accelerate the next one. Early in the plan only the extra payment is doing real damage to the priority debt; later, after one or two debts are gone, their freed minimums pile on, and the priority debt shrinks far faster than its own minimum alone could manage. This compounding of freed payments is why the last debt in any plan often falls surprisingly quickly. It is important to understand that rollover is not unique to either ordering -- both snowball and avalanche rely on it identically. The only thing the ordering decides is which debt receives the rolled-over money at each stage. So when one method finishes sooner, it is not because it rolls over and the other does not; both do. It is because the sequence in which debts clear, and therefore the timing of each rollover, is slightly different.
When the two methods agree
A surprising and useful case is when snowball and avalanche produce exactly the same result -- the same number of months and the same total interest. This happens when your debts are rank-aligned, meaning the order of balances from smallest to largest matches the order of APRs from highest to lowest. Consider a credit card of 60,000 at 18%, a personal loan of 120,000 at 12%, and a car loan of 250,000 at 6.5%. Here the smallest balance is also the highest-rate debt, the middle balance is the middle rate, and the largest balance is the lowest rate. Under those conditions both rules pick the same priority debt every single month, so they march through the debts in an identical sequence and post identical totals. The comparison tool will show two columns that look like copies of each other. Far from being a glitch, this is one of the most valuable things the comparison can tell you: for your particular mix, the choice of method has no financial consequence at all. You are free to pick whichever ordering feels easier to stay with, knowing it costs nothing either way. Only when a small balance carries a low rate, or a large balance carries a high rate, do the two rules start to diverge -- and that is precisely when running them side by side earns its keep.
Reading interest saved and months saved
The two numbers that drive a decision are interest saved and months saved, and they answer different questions. Interest saved is the difference in total interest between the two columns. Because avalanche always directs money at the highest rate first, it always produces the lowest interest the budget can achieve, so avalanche's interest figure is never higher than snowball's. The gap between them is what you would pay extra for the comfort of the snowball path. Months saved is the difference in total payoff time. This number is usually small -- often a single month -- because both methods spend the same constant budget and must extinguish the same total balance, so their finish lines are naturally close. The takeaway is to weight the two figures differently. Interest saved is the more meaningful and reliable measure of the financial gap; months saved is a secondary tie-breaker that rarely moves far. If you see a large interest gap with only a one-month difference, the comparison is telling you the methods cost noticeably different amounts but finish at nearly the same time. If both gaps are tiny, the methods are effectively interchangeable and your decision should rest on which one you will actually follow through to the end.
Why months saved is usually small
It can be counterintuitive that the two methods finish so close together when their interest costs differ. The reason lies in the constant budget. Every month, regardless of ordering, the same fixed amount is removed from your total debt -- part as interest and part as principal. The ordering changes how that fixed amount is split between interest and principal, but not the size of the payment itself. Avalanche reduces the interest portion slightly by killing high-rate balances first, which leaves a touch more of each payment to attack principal, which is why it finishes marginally sooner. But the effect on the calendar is modest because the budget is the dominant force, not the ordering. Picture two columns of water draining through pipes of the same total width: rearranging which pipe drains first changes the order the tanks empty but barely changes when the last drop falls. This is why a comparison tool should report interest saved as the headline difference and treat months saved as supporting detail. Expecting a dramatic difference in payoff date between the methods sets a false expectation. The honest framing is that ordering mostly changes the cost and the emotional path of the journey, while the budget you commit determines how long the journey takes.
Choosing a method you will actually finish
Because the financial gap between the two methods is often modest, the decision frequently comes down to behaviour rather than arithmetic. The two orderings feel very different in the early months. Snowball usually clears its first debt soonest because it attacks the smallest balance, delivering a concrete, visible win and one fewer payment to track. That early momentum keeps many people engaged through the long middle stretch of a payoff plan. Avalanche, by contrast, may keep a large high-rate balance in play for many months before the first debt disappears, which can feel like slow going even though it is quietly saving the most interest. The tool shows the month each debt clears under both rules, so you can see this contrast directly. If you know that visible progress keeps you motivated, the slightly higher interest cost of snowball may be a price worth paying, because a plan you complete always beats a cheaper plan you abandon halfway. If the raw numbers alone keep you disciplined, avalanche is the lower-cost route. The neutral point is that there is no single correct answer: the best method is the one you will follow to zero. Use the comparison to quantify what staying with snowball costs you, then decide whether that cost buys enough motivation to be worth it for your temperament.
What makes the gap between the methods wide or narrow
Once you know the two methods can tie, the next question is what makes their gap large rather than merely nonzero. The size of both interest saved and months saved is governed by how far your debts depart from rank alignment, and by the shape of that departure. The single biggest driver is a high-rate debt that also carries a large balance. When your most expensive rate sits on one of your bigger balances, the snowball ordering postpones it -- because that balance is not the smallest -- and every month it waits, that large balance manufactures interest at the steep rate. The avalanche attacks it immediately, so the interest it avoids is large, and the gap between the columns widens accordingly. The mirror situation also matters: a small balance carrying a low rate, which the snowball clears early while the avalanche leaves it for last, contributes little to the gap because a small low-rate balance accrues little interest no matter when it is paid. The width of your APR spread amplifies all of this. If every debt sits at a similar rate, reordering them barely changes how fast the combined balance compounds, so the gap stays narrow even when the balance and rate rankings disagree. Stretch the rates far apart -- one punishing card alongside several gentle loans -- and the cost of postponing the steep one grows, widening the gap. Balance concentration works the same way: a single dominant balance at a high rate produces a much larger gap than the same total spread thinly across several similar debts. Reading the comparison through these drivers tells you in advance whether the choice of method is a big decision or a small one. A wide APR spread with the steepest rate parked on a large balance signals a meaningful gap worth optimizing; clustered rates or a high rate already on a tiny balance signal that the two columns will land close together and the method choice will barely matter.
How the extra payment shapes the comparison
The extra monthly payment is the single most powerful lever in either method, and it also shapes the gap between them. Raising the extra payment increases the constant budget, so more of each month's money clears principal before it can accrue interest. The direct effect is that both the snowball and the avalanche finish sooner and cost less. The subtler effect is on the gap between the two columns: a larger extra payment usually narrows the interest difference, because when balances fall quickly there is less time for any debt to accumulate interest in the first place, so the ordering has less to influence. It rarely flips which method is cheaper -- avalanche minimizes interest by construction at any budget -- but it can shrink the advantage to the point of irrelevance. Lowering the extra payment does the reverse, stretching the plan out and giving high-rate debts more months to accrue, which tends to widen the avalanche advantage. The practical use is to treat the extra payment as a dial and watch both columns respond. If a modest increase collapses the gap between the methods, you can stop agonizing over which rule to use and focus on funding the extra payment instead. If the gap stays wide, the ordering choice matters more, and the comparison earns its place in your decision.
Reading the payoff order and the balance chart
Beyond the two headline totals, the comparison surfaces the sequence in which debts are cleared and a curve of the total balance falling over time. The payoff order lists each debt with the month it disappears and the interest it accumulated along the way, sorted by when it clears. Reading this list under each method reveals the personality of the two approaches: under snowball the first line is typically a small balance cleared early, while under avalanche the first line is often a larger, high-rate balance cleared later but with less interest bled into it. The balance curve shows the combined remaining debt dropping toward zero, and it usually steepens as the plan progresses because rollover keeps adding freed minimums to the attack. Comparing the two curves makes the small months-saved difference visual -- the lines track closely and cross the zero axis near the same point, which reinforces that the budget, not the ordering, sets the timeline. The per-debt interest figures are where the real difference shows: the high-rate debt accumulates noticeably less interest when avalanche attacks it first. Used together, the totals tell you the size of the decision, the payoff order tells you how each path feels month to month, and the curve confirms that both methods are spending the same money to reach the same finish line by slightly different routes.
Frequently asked questions
What is the difference between snowball and avalanche?
Both pay every minimum and put the extra on one debt. Avalanche picks the highest interest rate, which always costs the least in total. Snowball picks the smallest balance, which clears individual debts sooner and gives you a visible win earlier.
Which one should I actually use?
Avalanche if the interest saved is large and you are confident you will stick with it. Snowball if past attempts have stalled — a plan you finish beats a cheaper plan you abandon. This calculator shows the gap so you can decide with a number rather than a feeling.
Why must I keep paying every minimum?
Missing any minimum triggers late fees, can raise that debt's rate to a penalty APR, and is reported to the credit bureaus after 30 days. Every strategy here assumes all minimums are paid; only the extra is directed.
What does 'rolling' the payment mean?
When a debt clears, its minimum does not go back into your budget — it joins the extra and moves to the next debt. That is why payoff accelerates: the amount attacking your debt grows every time one is retired.
Should I include my mortgage?
Usually not. A mortgage rate is far below card rates and the interest may be deductible, so it rarely belongs in the same queue. Include cards, personal loans, auto loans, and student loans if their rates are high.
What if I can't afford any extra at all?
Then the timeline is your minimums alone, which on cards can run decades. Before adding debt strategies, the higher-value moves are lowering a rate — by asking, transferring, or consolidating — and freeing up any amount at all, since even $50 changes the shape.
Does this account for new spending?
No. The plan assumes you stop adding to these balances. If you keep charging on a card in the queue, the payoff date moves out and the strategy comparison stops meaning much.
What if a debt's interest is higher than my whole budget?
If total minimums plus extra cannot cover total interest, the balances grow no matter how you order them. The calculator says so rather than showing a payoff date. That is the point to look at consolidation, hardship programs, or a credit counselor.
Do I need an emergency fund first?
A small one, usually. Without any buffer the next unexpected bill goes on a card and undoes months of progress. A common approach is a starter fund of around $1,000, then the debt plan, then the full fund.
How does paying off debt affect my credit score?
Clearing revolving balances helps quickly, because utilization falls. Clearing an installment loan helps less, and closing it can even dip your score slightly by reducing your credit mix — which is not a reason to keep paying interest.
Should I negotiate rates before starting?
Yes, it is the cheapest hour you will spend. Calling to ask for a lower APR succeeds more often than people expect, and every point off the rate makes the whole plan shorter without costing you a dollar more each month.
What if my income changes mid-plan?
Come back and change the extra amount. The order stays valid; only the timeline moves. The plan is not a contract — it is a queue, and the queue works at any budget.