Debt Payoff Calculator

See how long until you are debt-free and how much interest you will pay. Raise the payment to see it shrink fast.

How the Debt Payoff Calculator works

For one debt, this tool solves a single equation for the number of months it takes to clear the balance at a fixed payment, then derives total interest from that; for several debts it runs a month-by-month simulation so each payoff can roll its payment onto the next. The single-debt formula is:

Months = -ln(1 - (B x i) / P) / ln(1 + i), where B is the current balance, P is your fixed monthly payment, and i is the monthly interest rate (annual APR divided by 12, as a decimal). Once months are known, total interest = (P x months) - B.

Here is exactly what happens internally for a single debt:

1. Convert the rate. A 19% APR becomes i = 0.19 / 12 = 0.0158333 per month.
2. Compute one month of interest. B x i. On an $8,000 balance at 19%, that is $126.67 in the first month.
3. Check the payment is large enough. If your payment is less than or equal to B x i, the balance never falls and the formula has no solution. The tool flags this instead of returning a number.
4. Solve for months using the natural-log formula above, then round up to the next whole payment.
5. Total the cost. Multiply the payment by the months and subtract the starting balance to isolate interest.

Edge cases it handles: a 0% APR debt skips the log entirely and uses months = B / P. A payment at or below the monthly interest charge triggers the "never pays off" warning. For multiple debts, the tool switches to a month-by-month simulation rather than the closed-form equation, because each cleared debt frees its payment to roll onto the next one - that rollover is what the single-debt formula cannot capture, and it is the engine behind the avalanche and snowball plans this page is built around.

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Example calculation

Example 1 - one debt, the power of a bigger payment. You owe $8,000 at a 19% APR. At a $200 monthly payment, the simulation runs 64 months and racks up $4,773.54 in interest (the formula returns 63.87 months, which rounds up to the 64th payment). Now raise the payment to $350: payoff drops to 29 months and interest falls to $2,010.26. Adding $150 a month clears the debt 35 months sooner and saves $2,763.28 - the single biggest lever you control.

Example 2 - avalanche vs snowball on three debts. You have a $2,500 card at 25.99%, a $7,000 card at 18%, and a $4,000 loan at 6.5% (total $13,500), with $600 a month to spend. The avalanche attacks the 25.99% card first and clears everything in 27 months for $2,286.01 interest. The snowball attacks the $2,500 balance first; it also finishes in 27 months but costs $2,601.17 - $315.16 more - because it lets the 25.99% card keep accruing longer.

Example 3 - why minimum-only payments fail. Keep the same three debts but pay only the fixed minimums on each ($75 + $175 + $100 = $350 total, with no rollover): the slowest debt drags the picture out to 62 months and $6,271.08 in interest. Versus the avalanche, paying minimums costs an extra 35 months and $3,985.07.

Plan	Monthly outlay	Months to debt-free	Total interest	Total paid
Minimums only (no rollover)	$350	62	$6,271.08	$19,771.08
Snowball	$600	27	$2,601.17	$16,101.17
Avalanche	$600	27	$2,286.01	$15,786.01

Same $13,500 of debt, three very different outcomes. The jump from minimums to a fixed $600 budget saves the most; the choice between avalanche and snowball is the fine-tuning on top.

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Tips for using the Debt Payoff Calculator

• Find your debt-free date by working backward from a target, not forward from a payment. Decide you want to be clear in 24 months, then raise the payment until the tool shows 24 - it reframes the budget conversation from 'what can I spare' to 'what will it take.'
• When you clear the first debt, roll its entire payment onto the next one instead of pocketing it. That rollover is the whole point of avalanche and snowball; skip it and a 27-month plan stretches past 40 months.
• Run avalanche and snowball side by side before choosing. If the interest gap is small (a few hundred dollars), pick snowball for the early wins; if it is large, the discipline of avalanche pays for itself.
• Check whether any single payment is at or below that debt's monthly interest. If it is, the balance grows every month no matter how long you pay - the tool flags this, and it usually means that one debt needs a higher payment or a balance transfer.
• Apply windfalls (tax refunds, bonuses, a side-gig month) directly to your highest-APR balance as a lump sum, and model it by lowering that debt's starting balance, not the payment. A $2,000 lump on a $12,000 balance at 19% can cut roughly 9 months and over $1,500 in interest.
• List every debt's APR before you start, not just the balances. People default to attacking the loan with the scariest balance, but a small 26% card quietly costs more per dollar than a large 6% loan.
• Keep paying the minimum on every other debt while you attack the target. Missing a minimum on a back-burner debt triggers late fees and penalty APRs that can erase a month of progress elsewhere.
• Recompute the moment a rate changes. Variable-rate cards reprice; if an 18% card jumps to 24%, it may leapfrog another debt in the avalanche order and should become the new target.
• Treat a 0% balance-transfer offer as a deadline, not a discount. Set the payment that clears the full balance before the promo ends, because the snap-back rate afterward can undo the savings.
• Don't let the budgeted total shrink as balances fall. The single biggest failure mode is 'payment creep down' - keep the total monthly outlay fixed until the last debt is gone, even though it feels like you could ease off.

Avalanche vs snowball: which debt to attack first

The avalanche method pays the highest-APR debt first and is mathematically the cheapest; the snowball method pays the smallest balance first and is the most motivating. Both pay minimums on everything else and throw all spare money at one target.

The difference is purely the order. Avalanche minimizes interest because it kills your most expensive dollars first. Snowball minimizes the time to your first win - clearing a small balance fast gives a psychological boost that keeps many people in the game. Using the three debts from Example 2 above:

	Avalanche	Snowball
Attacks first	Highest APR (25.99%)	Smallest balance ($2,500)
Best at	Lowest total interest	Fastest first payoff / motivation
Total interest	$2,286.01	$2,601.17
Months to debt-free	27	27
Extra cost vs avalanche	$0	$315.16

Here the timelines happen to match and the gap is only $315 - that is common when the highest-APR debt is also fairly small. The wider your balances and rates spread, the more avalanche pulls ahead. Pick avalanche if you are driven by the math; pick snowball if you have abandoned payoff plans before and need momentum. Either beats doing nothing. If a single card is your real problem, the credit card payoff calculator drills into one revolving balance.

Why minimum-only payments are a trap

Paying only the minimum keeps you in debt for years because most of each payment goes to interest, not principal. Example 3 above is the proof: the same $13,500 takes 62 months and $6,271 in interest when you only cover the minimums, versus 27 months and $2,286 once you commit a fixed $600 and roll freed payments forward.

The trap deepens with percentage-based minimums (often around 2% of the balance, or 1% plus interest) because as the balance falls the required minimum falls too - so your payment shrinks just when you should keep pushing. That declining payment is exactly why a single revolving balance can linger past a decade. The strategy fix for any debt is the same: lock a fixed-dollar total and never let it drop, even as individual balances disappear, and keep redirecting each freed payment onto the next target. The size of your payment matters far more than which method you choose - moving from minimums to a real budget is the big win; avalanche vs snowball is the tweak. For the issuer-side mechanics of how a card's shrinking minimum is calculated, see the credit card minimum payment calculator.

How to build the math by hand or in Excel

You can reproduce the single-debt payoff with one spreadsheet function: NPER. It returns the number of payments for a given balance, rate, and payment.

The formula is:

=NPER(APR/12, -payment, balance)

For the $8,000 debt at 19% with a $350 payment, =NPER(0.19/12, -350, 8000) returns 28.6, which rounds up to 29 months - matching the tool. The payment is entered as a negative because it is cash leaving your pocket. To get the cost:

• Total paid: =payment * NPER(APR/12, -payment, balance)
• Total interest: =(payment * NPER(APR/12, -payment, balance)) - balance

To flip the question and find the payment that hits a target date, use =PMT(APR/12, target_months, -balance). By hand, the one risky step is the natural log in n = -ln(1 - (B x i) / P) / ln(1 + i): compute (B x i) / P first, subtract from 1, then take ln of both that result and (1 + i). A multi-debt avalanche or snowball plan cannot live in a single cell - it needs a month-by-month table where each cleared debt's payment is added to the next - which is precisely the simulation this calculator runs for you.

Is your payoff timeline good? Reference benchmarks

A healthy rule of thumb is to clear high-interest consumer debt (cards, personal loans) within 18 to 36 months; anything past 5 years on revolving debt is a warning sign. There is no official standard, but these reference points help you judge the plan the tool produces:

Timeline to clear non-mortgage debt	Read it as
Under 12 months	Aggressive - excellent if the budget is sustainable
12-36 months	Healthy target zone for most consumer debt
3-5 years	Acceptable for large balances; watch total interest
Over 5 years (revolving)	Red flag - rate is likely too high or payment too low

The other half of the picture is how much of your income the debt consumes. Lenders generally want total monthly debt payments under 36% of gross income, and that ceiling is a useful self-check - run yours through the debt-to-income ratio calculator. If your DTI is high and the tool's timeline is long, raising the payment may require freeing cash elsewhere before the payoff math can improve.

Debt payoff time and interest: a $15,000 reference grid

This quick-reference shows how long $15,000 takes to clear, and the total interest paid, at three common APRs and three monthly payments. Every figure is recomputed by month-by-month simulation (interest = balance x APR / 12 each month). Two patterns stand out: a higher payment cuts both time and interest sharply, and at 24% APR a $300 payment never clears the debt because $15,000 x 24% / 12 = $300 of interest in the first month, so the payment exactly equals the interest and nothing touches principal.

APR	$300/month	$500/month	$700/month
12%	70 mo / $5,899 interest	36 mo / $2,923	25 mo / $1,966
18%	94 mo / $12,934	41 mo / $5,077	27 mo / $3,231
24%	Never pays off	47 mo / $8,137	29 mo / $4,783

Takeaway: on the 18% row, raising the payment from $300 to $700 saves about $9,703 in interest and 67 months. The lesson the grid drives home is that on high-rate debt the payment size, not the strategy label, is what bends the curve. Model your exact balance and rate at the top of this page.

Advanced moves: lump sums, transfers, and consolidation

Three tactics can compress your timeline beyond just raising the monthly payment: one-time lump sums, balance transfers, and a consolidation loan.

• Lump sums: a tax refund or bonus applied to your highest-APR balance cuts both the principal and every future interest charge on it. Model it by lowering that debt's starting balance, not the payment - a $2,000 windfall on a $12,000 balance at 19% trims roughly 9 months and over $1,500 of interest.
• Balance transfers: moving a 25% card to a 0% promo can route nearly your whole payment to principal during the promo window. Set a payment that clears the balance before the promo ends, and weigh the transfer fee (often 3-5%).
• Consolidation: replacing several high-rate debts with one fixed loan can lower your blended rate and simplify the plan - but only if the new APR is genuinely lower and you do not stretch the term. Compare the new loan in the loan calculator against your current avalanche plan from this page.

Each tactic changes one input. The discipline that makes any of them work is unchanged: keep the freed-up cash inside the payoff, never back in your spending.

Common mistakes to avoid

Most debt-payoff plans fail not on the math but on a handful of avoidable behaviors.

• Letting the payment shrink as balances fall. The biggest killer. Lock a fixed-dollar total and hold it until the last debt is gone.
• Not rolling freed payments forward. When debt one is cleared, its payment must move onto debt two. Pocketing it restarts the slow grind.
• Sorting by balance when you mean to save money. Attacking the biggest balance feels productive but can ignore a smaller, higher-APR debt that costs more per dollar - that is the avalanche's whole argument.
• Missing a minimum on a back-burner debt. Late fees and penalty APRs can wipe out a month of progress elsewhere.
• Ignoring the never-pays-off warning. If a payment is at or below that debt's monthly interest, no amount of time clears it - the balance grows.
• Treating a 0% transfer as free. The promo is a deadline. Plan to finish before the rate snaps back, and account for the transfer fee.

What this tool covers (and when to use a sibling)

This is the general-purpose, strategy-first payoff tool - use it for any mix of fixed-rate debts and to choose between avalanche and snowball. It is deliberately broad so it can model a whole debt picture at once and run the rollover simulation the strategies depend on.

Your situation	Use this calculator?	Why / better tool
Multiple debts, picking a strategy	Yes	This is the avalanche-vs-snowball home
One fixed debt, find payoff date	Yes	Solves months and interest directly
A single credit card	Maybe	The credit card payoff calculator handles card-specific quirks
Understanding the shrinking minimum	No	Use the minimum payment calculator
Checking if you can afford the debt at all	No	Use the debt-to-income calculator

If your debts are fixed-rate and you want to plan the order and timeline, this page is the right home. The siblings zoom into one slice - a single card, the minimum-payment mechanics, or affordability - that this strategy tool intentionally stays above. Once you are debt-free, redirect that same monthly payment into the savings goal calculator so the habit keeps building wealth, and park a starter cushion using the emergency fund calculator so a surprise bill doesn't send you back into debt.

Related on this site

Credit Card Payoff Calculator · Debt-to-Income Ratio Calculator · Loan Calculator · Emergency Fund Calculator · Savings Goal Calculator · Credit Card Minimum Payment Calculator

For a related deep dive, see CFPB debt help resources.

Debt Payoff Calculator — frequently asked questions

Why so slow?

On high-APR debt, most of a small payment is interest, so the balance barely moves.

Fastest method?

Pay above the minimum and target the highest-APR balance first (avalanche method).

Snowball or avalanche method?

Avalanche (highest rate first) saves the most money; snowball (smallest balance first) builds motivation.

Why does payoff take so long?

On high-APR debt most of a small payment is interest, so principal barely moves.

How much faster do I pay off $10,000 at 22% APR if I pay $400 instead of $250 a month?

<p>Raising the payment from $250 to $400 a month cuts payoff from about <strong>73 months to 34 months</strong> and slashes interest from roughly $8,189 to $3,500 on a $10,000 balance at 22% APR.</p><p>That extra $150 a month saves around <strong>$4,689 in interest</strong> and over three years of payments. The pattern is universal: a higher fixed payment is the single biggest lever on any debt. Model your own numbers in the <a href="/debt-payoff-calculator/">debt payoff calculator</a>.</p>

What is the avalanche method and exactly how much can it save versus snowball?

<p>The avalanche method directs every extra dollar to your <strong>highest-APR debt first</strong>, which is mathematically the cheapest path; snowball targets the smallest balance first for quick wins.</p><p>Example: a $1,000 loan at 12% plus a $6,000 loan at 26%, with a $300 monthly budget. Avalanche (26% first) clears both in <strong>32 months for about $2,446 interest</strong>; snowball (the $1,000 first) takes 33 months and about $2,781 - roughly <strong>$335 more</strong>. Avalanche wins on cost; snowball wins on motivation.</p>

Should I use snowball or avalanche if my smallest debt also has the highest rate?

<p>Use either - they give the identical plan when your smallest balance is also your highest-rate debt.</p><p>Example: $2,000 at 28%, $5,000 at 18%, and $8,000 at 12% on a $600 monthly budget. Both methods target the $2,000/28% debt first and finish in <strong>30 months for about $2,881 interest</strong>. The avalanche-vs-snowball debate only matters when balance order and rate order disagree. Map both orders in the <a href="/debt-payoff-calculator/">debt payoff calculator</a>.</p>

How long to pay off $15,000 at 19% APR on $300 a month versus $500?

<p>At $300 a month, $15,000 at 19% APR takes about <strong>100 months</strong> (over 8 years) and costs roughly $14,956 in interest - nearly the original balance again.</p><p>Bump to $500 a month and it drops to about <strong>42 months</strong> with around $5,509 interest. The extra $200 a month saves close to <strong>$9,447</strong> and 58 months. High-rate balances reward higher payments steeply, not linearly.</p>

Why do minimum-only payments take decades to clear a balance?

<p>Minimum payments stay near decades-long payoff because they are a small percentage of a shrinking balance, so principal barely falls.</p><p>Example: $8,000 at 21% APR on a 2%-of-balance minimum (floor $25) takes about <strong>770 months and roughly $43,184 in interest</strong>. A fixed $300 a month clears the same debt in <strong>37 months for about $2,871</strong>. Paying a flat amount above the first minimum breaks the trap. See the <a href="/credit-card-minimum-payment-calculator/">minimum payment calculator</a>.</p>

What payment do I need so a $6,000 balance at 24% APR actually goes down?

<p>You must pay more than the monthly interest, which on $6,000 at 24% APR is exactly <strong>$120</strong> ($6,000 x 0.02). A $120 payment never reduces the balance at all.</p><p>At $130 a month it does eventually clear, but takes about <strong>130 months and roughly $10,839 in interest</strong>. The lesson: any payment at or below monthly interest is a permanent treadmill. Use the <a href="/debt-payoff-calculator/">debt payoff calculator</a> to find your floor.</p>

How do I calculate months to pay off a debt by hand?

<p>Use the formula <strong>n = -ln(1 - rB/P) / ln(1 + r)</strong>, where B is the balance, P the monthly payment, and r the monthly rate (APR / 12, as a decimal).</p><p>Example: $12,000 at 16% gives r = 0.013333. For P = $350: -ln(1 - 0.013333 x 12,000 / 350) / ln(1.013333) = <strong>about 46.1, so 47 months</strong>. A simulation confirms 47 months and roughly $4,143 interest. If 1 - rB/P is zero or negative, the payment never clears the debt.</p>

How much does paying $600 instead of $400 save on a $20,000 loan at 18% APR?

<p>Paying $600 a month instead of $400 on $20,000 at 18% APR cuts payoff from about <strong>94 months to 47 months</strong> - exactly half the time.</p><p>Interest drops from roughly $17,245 to $7,934, a saving of about <strong>$9,310</strong>. Notice the interest at $400 nearly equals the loan itself; at 18% APR, a slow payment almost doubles your cost. Adding 50% to the payment more than doubles the speed.</p>

Does a debt consolidation loan actually save money, with numbers?

<p>A consolidation loan saves money only if it lowers your effective rate enough to beat the new term and any fees.</p><p>Example: $18,000 at a blended 22% APR paid at $450 a month runs about <strong>73 months and $14,740 interest</strong>. Consolidate the same $18,000 to 12% APR at $450 and it finishes in <strong>52 months for about $5,102</strong> - roughly <strong>$9,638 saved</strong>. The catch: keep the payment up and stop new charges, or the gain evaporates.</p>

Is paying double the minimum worth it on a $7,000 card at 23% APR?

<p>Doubling the minimum is overwhelmingly worth it. Holding the first minimum flat at about $140 (2% of $7,000) drags payoff out to roughly <strong>168 months and $16,436 in interest</strong>.</p><p>Paying a fixed $280 a month - double that first minimum - clears it in about <strong>35 months for $2,621</strong>. That single change saves close to <strong>$13,815</strong> and over 11 years. The biggest wins come from locking a fixed payment well above the minimum.</p>

How much sooner does a $2,000 lump-sum payment clear $12,000 at 19% APR?

<p>Applying a $2,000 windfall to a $12,000 balance at 19% APR, while keeping $400 a month, finishes the debt about <strong>9 months sooner</strong> - 33 months instead of 42.</p><p>Interest falls from roughly $4,407 to $2,831, a saving near <strong>$1,576</strong> on top of the $2,000 you paid. Lump sums work best applied to your highest-APR balance, the avalanche principle in action. Test windfalls in the <a href="/debt-payoff-calculator/">debt payoff calculator</a>.</p>

How much extra per month roughly halves payoff time on $10,000 at 20% APR?

<p>Adding about <strong>$150 a month</strong> roughly halves the timeline: $10,000 at 20% APR takes about 50 months at $300/mo but only <strong>28 months at $450/mo</strong>.</p><p>Interest drops from roughly $4,718 to $2,595, saving about <strong>$2,123</strong>. As a rule of thumb on high-rate debt, a 50% larger payment cuts the term close to half because principal falls faster every cycle, accelerating the next reduction.</p>

Is a 0% balance transfer worth it, and what payment clears $9,000 in 18 months?

<p>A 0% balance transfer is worth it only if you actually clear the balance before the promo ends, since interest snaps back afterward.</p><p>To pay off $9,000 over an 18-month 0% window you need about <strong>$500 a month</strong> ($9,000 / 18), and you pay essentially <strong>$0 interest</strong> aside from any transfer fee (often 3-5%, so roughly $270-$450 here). Miss the deadline and the regular APR applies to whatever remains.</p>

How much faster is $250 versus $150 a month on a $5,000 debt at 24% APR?

<p>Paying $250 instead of $150 on $5,000 at 24% APR cuts payoff from about <strong>56 months to 26 months</strong> - less than half the time.</p><p>Interest drops from roughly $3,322 to $1,449, a saving near <strong>$1,873</strong>. On a small but high-rate balance, even $100 more a month is dramatic because the 24% rate makes every extra dollar of principal especially valuable. Run your figures in the <a href="/debt-payoff-calculator/">debt payoff calculator</a>.</p>

How do I build a multi-debt payoff plan step by step?

<p>List every debt with its balance, APR, and minimum; pay all minimums each month, then send every spare dollar to one target debt until it is gone, then roll that freed-up amount to the next.</p><p>Choose the target by <strong>highest APR (avalanche, cheapest)</strong> or <strong>smallest balance (snowball, most motivating)</strong>. On a fixed $600 budget across three sample debts, avalanche cleared the portfolio in 30 months for about $2,881. Keep the total budget constant as balances disappear - that rollover is what accelerates the plan.</p>

Is it better to pay off the highest-rate debt or the one with the smallest balance?

<p>Pay the highest-rate debt first if you want the lowest total cost; pay the smallest balance first if you need early wins to stay consistent.</p><p>With a $1,000 debt at 12% and a $6,000 debt at 26% on $300 a month, highest-rate-first (avalanche) costs about <strong>$2,446</strong>, while smallest-first (snowball) costs about <strong>$2,781</strong> - a $335 gap. Pick avalanche for math, snowball for behavior; the difference shrinks when balances are similar.</p>

Guides & articles

• Avalanche vs Snowball: Which Debt Should You Pay Off First?
• Why Paying More Than the Minimum Clears Debt Far Faster

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Credit Card Payoff Calculator · Credit Card Minimum Payment Calculator · Debt-to-Income Ratio Calculator · Mortgage Calculator · Loan Calculator · Auto Loan Calculator