Debt Payoff Calculator

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Debt Payoff Calculator

List up to six debts with their balances, APRs and minimum payments, enter what you can pay each month, and compare the avalanche and the snowball side by side: months, payoff date, total interest, the order the debts clear and the saving over minimum payments.

Debt, optional nameBalance, $APR, %Minimum, $

Order the debts are paid offmonth of the last payment on each
Every figuretap a card to copy its value

Balance by debt, month by month

Total balance: avalanche, snowball and minimums only

Each debt under each strategy
The same debts at other budgets

Interest each month = balance × APR ÷ 12, rounded to the cent. Every minimum is paid and the rest goes to the target, the highest APR for the avalanche or the smallest starting balance for the snowball; a cleared debt’s payment rolls on to the next. Minimums are held fixed, with no new charges, fees or rate changes, and the first payment falls next month. The CSV, image and printed report contain the values you entered, nothing preloaded.

How to use this tool

Put each debt on its own row with an optional name, the balance, the APR and the minimum payment from the latest statement, up to six rows. Then enter the monthly amount, either as the total for all the debts or as the extra on top of the minimums, and pick the plan to show. Both plans are always worked out, and the tables set them side by side with minimums only.

The input people most often get wrong is the monthly amount. In total mode it must include the minimums, so entering only the spare $259 when the minimums add up to $641 makes the budget too small, and the calculator says so instead of producing a plan. For a credit card, enter the minimum you will keep paying, usually today’s, not the smaller one the issuer asks for as the balance falls.

What the calculation is doing

The plan runs one month at a time. Interest is added to every debt, monthly interest = balance × APR ÷ 12, rounded to the cent, and each debt gets its minimum. The rest of the budget goes to the target: the highest APR under the avalanche, the smallest starting balance under the snowball, with ties going to the smaller balance and the higher rate respectively.

When the target is paid off, its payment moves to the next debt in line, so the monthly total stays the same until the last debt is gone. The Consumer Financial Protection Bureau calls this creating a snowball of payments, and both methods use it; they differ only in the order. Minimums only, the benchmark for the saving, pays each debt its own minimum and rolls nothing over.

For one debt paid a fixed amount P, the months have a closed form: n = −ln(1 − r × B ÷ P) ÷ ln(1 + r), with B the balance and r = APR ÷ 12, and the simulation reproduces it. With several debts there is no neat formula, because each payment changes whenever another debt clears.

Stacked bars of the monthly payment to each of three debts over 29 months at $900 a month. Under the avalanche Card A at 24.99% gets $484 until month 19, Card B gets $550 until month 22 and the car loan gets all $900 from then on. Under the snowball Card B gets $325 until month 8, Card A gets $550 until month 23 and the car loan gets $900. A second panel compares total interest: $7,806 on minimums only, and avalanche against snowball at $641, $700, $900 and $1,200 a month, where the gap between methods is $203 at $900 but raising the budget to $1,200 a month saves $1,200 of interest
The bars stay the same height every month: the budget never changes, only where it goes. That is why both methods finish in month 29 here, and why the size of the budget moves the interest far more than the choice of method.

Avalanche or snowball: what the numbers say

On arithmetic the avalanche wins, because each extra dollar goes where it stops the most interest. With the default debts at $900 a month it pays $3,528.88 of interest against $3,732.26 for the snowball, $203.38 less. Both finish in month 29: the finish is set mostly by how much goes in each month, and the car loan, the largest balance at the lowest rate, is last under both.

The gap grows when the budget is tight and the rates are far apart. The Federal Reserve Bank of St. Louis worked through two cards, $5,000 at 20% and $2,500 at 14%, paid with $200 a month. The avalanche takes 4 years 7 months and $3,396.70 of interest, the snowball 4 years 10 months and $3,976.93, a gap of $580.

What the snowball buys is an early win: it clears Card B in month 8, where the avalanche clears its first debt in month 19. David Gal and Blakeley McShane at Kellogg studied about 6,000 people in a debt settlement program and found that closing accounts, independent of their dollar balances, predicted who eliminated their debt. If an early paid off account keeps you going, the tool shows what it costs, here $203.38.

The budget matters more than the method. Raising it from $900 to $1,000 cuts the avalanche interest by $532.75, more than twice the gap between methods, and finishes 4 months sooner. Even with no extra, rolling each freed minimum on finishes in 46 months instead of 58.

Two cards and a car loan at different budgets

Card A $7,500 at 24.99% (minimum $225), Card B $2,200 at 18.5% ($66) and a car loan of $12,000 at 7.14% ($350), paid with the total shown each month.

Paid a monthAvalancheInterestSnowballInterestAvalanche saves
$641, no rolloverminimums only4 years 10 months, $7,806.37samenot defined
$641minimums, rolled over3 years 10 months$7,310.213 years 10 months$7,321.49$11.28
$7003 years 4 months$5,842.313 years 4 months$6,091.26$248.95
$8002 years 9 months$4,349.252 years 9 months$4,594.86$245.61
$9002 years 5 months$3,528.882 years 5 months$3,732.26$203.38
$1,0002 years 1 month$2,996.132 years 1 month$3,164.77$168.64
$1,2001 year 9 months$2,328.511 year 9 months$2,454.38$125.87
$1,5001 year 4 months$1,773.801 year 4 months$1,862.66$88.86
$2,0001 year$1,293.011 year$1,353.02$60.01

A worked example you can check on paper

The default debts at $900 a month, avalanche. First month interest: 7,500 × 0.2499 ÷ 12 = $156.19 on Card A, 2,200 × 0.185 ÷ 12 = $33.92 on Card B and 12,000 × 0.0714 ÷ 12 = $71.40 on the car loan, $261.51 in all. The minimums are 225 + 66 + 350 = $641, so 900 − 641 = $259 is extra, and it goes to Card A, the highest rate.

After the first payment the balances are 7,500 + 156.19 − 484 = $7,172.19, 2,200 + 33.92 − 66 = $2,167.92 and 12,000 + 71.40 − 350 = $11,721.40. Card A is paid off in month 19. From month 20, Card B gets 66 + 484 = $550 a month and clears in month 22; from month 23 the car loan gets 350 + 550 = $900 and clears in month 29, with a last payment of $28.88. Total paid $25,228.88, less the $21,700 owed, is $3,528.88 of interest.

To check one debt on its own, take Card B at its $66 minimum: n = −ln(1 − 0.0154167 × 2,200 ÷ 66) ÷ ln(1.0154167) = 47.15, so 48 payments, the month shown for Card B under minimums only.

Mistakes that catch people out

Entering the extra as the total. In total mode the amount must cover the minimums too. Switch the first box if the number you have is the extra.

Letting card minimums shrink. Issuers lower the minimum as the balance falls, and paying only what is asked takes money out of the plan.

Spending the freed payment. Without the rollover the default debts take 58 months instead of 46, even with no extra money.

Planning on a promotional rate. A 0% offer ends. Enter the rate that applies afterwards, or plan to clear that debt before it does.

Popular calculations

Each opens the calculator with those debts, budget and plan filled in, ready to change.

Two cards and a car loan

Card A $7,500 at 24.99%, Card B $2,200 at 18.5% and a $12,000 car loan at 7.14%, minimums $641.

$700 a month, avalanche: 40 months, $5,842 interest$700 a month, snowball: 40 months, $6,091 interest$900 a month, avalanche: 29 months, $3,529 interest$900 a month, snowball: 29 months, $3,732 interest$1,200 a month, avalanche: 21 months, $2,329 interest$1,200 a month, snowball: 21 months, $2,454 interest$1,500 a month, avalanche: 16 months, $1,774 interest

The same debts, extra on top of the minimums

No extra, minimums rolled over: 46 months$100 extra a month, avalanche: 37 months$250 extra a month, avalanche: 29 months$250 extra a month, snowball: 29 months$500 extra a month, avalanche: 22 months

A student loan and two cards

Card A $4,800 at 27.24%, Card B $1,500 at 19.99% and a $28,000 student loan at 6.52%.

$600 a month, avalanche: 73 months, $9,226 interest$800 a month, avalanche: 51 months, $5,900 interest$800 a month, snowball: 51 months, $6,032 interest$1,000 a month, avalanche: 39 months, $4,434 interest$1,000 a month, snowball: 39 months, $4,520 interest

Three credit cards

$3,200 at 29.99%, $5,400 at 21.49% and $900 at 17.99%.

$400 a month, avalanche: 33 months, $3,318 interest$400 a month, snowball: 33 months, $3,492 interest$500 a month, avalanche: 24 months, $2,385 interest$500 a month, snowball: 25 months, $2,514 interest$750 a month, avalanche: 15 months, $1,441 interest

Five debts, from cards to a student loan

Two cards, a personal loan, a car loan and a student loan, $55,100 in all.

$1,500 a month, avalanche: 43 months, $9,286 interest$1,500 a month, snowball: 44 months, $9,432 interest$2,000 a month, avalanche: 31 months, $6,204 interest

The St. Louis Fed example

$200 a month, avalanche: 4 years 7 months, $3,396.70 interest$200 a month, snowball: 4 years 10 months, $3,976.93 interest

One debt at a time

$5,000 at 22%, $200 a month: 34 months$10,000 at 22%, $500 a month: 26 months$20,000 at 11.86%, $700 a month: 34 months

How this was checked

The engine reproduces the published example from the Federal Reserve Bank of St. Louis (Page One Economics, February 2023): 55 months and $3,396.70 of interest for the higher rate first, 58 months and $3,976.93 for the smaller balance first, against the published 4 years 7 months, $3,396 and 4 years 10 months, $3,976. For one debt it matches the textbook case in Terri Manthey’s College Algebra for the Managerial Sciences, $140,000 at 6% paid at $1,000 a month in 20.12 years, which is 242 payments.

A second simulator, written separately in whole cents with the targets sorted afresh each month, agreed to the cent with the engine on 6,000 plans from 3,000 random sets of one to six debts: the months, the payoff month of every debt and its interest. In 4,998 single debt cases the months equalled the closed form rounded up, and the results matched the site’s credit card payoff calculator, all but seven to the cent and those by one cent. In those random sets the snowball never cost less interest or finished sooner than the avalanche, and the two finished in the same month two times in three.

Card issuers charge a daily rate, the APR divided by 360 or 365 according to the Consumer Financial Protection Bureau, so real statements can differ from the APR ÷ 12 used here by a few dollars. Every address above was opened and checked for a distinct title, the right answer, working charts and clean exports at desktop and phone widths.

Common questions

What is the difference between the debt avalanche and the debt snowball?

Both pay the minimum on every debt, put the spare money on one target and roll that payment on to the next target when the first is gone. The avalanche targets the highest APR first, the snowball the smallest balance. The monthly total is the same; only the order changes.

Which method saves more money?

The avalanche. In 3,000 random sets of debts it never cost more interest or took longer than the snowball. For two cards and a car loan paid at $900 a month it saves $203.38 of interest; in the St. Louis Fed example of two cards at $200 a month it saves $580 and three months. The snowball clears a first debt sooner.

What happens to the payment when a debt is paid off?

It moves to the next debt in line, so the monthly total stays the same until everything is gone. In the default example Card A takes $484 a month until month 19; from month 20 Card B gets its own $66 plus that $484, $550 in all.

What if my budget is less than the total of the minimum payments?

The calculator stops and shows how far short the budget is, because every minimum has to be paid to keep the accounts current. The Consumer Financial Protection Bureau advises contacting the card company straight away if you cannot pay, and notes that many credit counseling organizations are nonprofits.

Can I include a car loan, student loan or mortgage?

Yes: enter the balance, the rate and the scheduled payment as the minimum. Large loans at low rates usually come last under both methods. Federal student loans have income based repayment plans and protections that a card lacks, worth weighing before sending them extra.

Why does my lender show slightly different numbers?

Lenders charge interest daily, at the APR divided by 365 or 360, while this calculator uses the APR divided by 12 each month and holds each minimum fixed. The difference is usually a few dollars a year per debt.

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