Finance

Debt Payoff Calculator

Q: How do I find the monthly payment needed to be debt-free by a certain date?

Switch the calculator to target-date mode and enter the number of months you want. It reverse-solves the amortization formula, P = B x i x (1+i)^n / ((1+i)^n - 1), to give the exact payment. For a 5,000 balance at 19.99% APR over 24 months, that is about 254 a month.

Q: Why does my debt never get paid off at the minimum payment?

If the payment is less than the interest charged that month, the balance grows instead of shrinking. On a 5,000 balance at 19.99% APR, the first month of interest is about 83, so any payment at or below that makes no progress and the debt never clears.

Q: How much do extra payments save me?

Every extra dollar goes straight to principal, which lowers future interest. On a 5,000 balance at 19.99% APR, paying 300 instead of 200 a month cuts payoff from 33 months to 20 and saves over 600 in interest. The calculator shows your exact saving in the results.

Q: Should I use the avalanche or snowball method for multiple debts?

The avalanche method pays the highest-APR debt first and saves the most interest. The snowball method pays the smallest balance first for quick motivational wins. Avalanche is mathematically cheaper, but the best method is the one you will actually stick with.

See how long it takes to clear a debt at a fixed monthly payment, or flip to target-date mode to solve for the exact payment needed to be debt-free by a chosen month. Add extra monthly or one-time payments to watch the timeline and interest drop, and see your full month-by-month schedule.

By Sarah Klein, CFP · Updated June 4, 2026

Currency

Time to pay off1-3 years

33months

Total interest paid$1,521.02

Total amount paid$6,521.02

Principal (the balance)$5,000.00

Principal$5,000.00 77%
Interest$1,521.02 23%

Month

Chart data
Month	Balance
$0.0	$5k
$1.0	$5k
$2.0	$5k
$3.0	$5k
$4.0	$5k
$5.0	$4k
$6.0	$4k
$7.0	$4k
$8.0	$4k
$9.0	$4k
$10.0	$4k
$11.0	$4k
$12.0	$3k
$13.0	$3k
$14.0	$3k
$15.0	$3k
$16.0	$3k
$17.0	$3k
$18.0	$3k
$19.0	$2k
$20.0	$2k
$21.0	$2k
$22.0	$2k
$23.0	$2k
$24.0	$2k
$25.0	$1k
$26.0	$1k
$27.0	$1k
$28.0	$879
$29.0	$694
$30.0	$505
$31.0	$314
$32.0	$119
$33.0	$0.0

You will be debt-free in about 2 yr 9 mo and pay 1,521 in interest.

Interest adds roughly 30% on top of the balance you borrowed.
Paying even a little extra each month shortens the timeline and cuts interest, because interest compounds on the remaining balance.
Higher-APR debts cost more per dollar, so target those first if you are juggling several (the avalanche method).

Next stepAdd an extra monthly payment or a one-time lump and watch how fast the payoff time and total interest drop.

Convert the APR to a monthly interest rate19.99% / 12
1.6658% per month
First month of interest on the balance5,000 x 1.6658%
83.29
Step the balance forward each month: add interest, subtract the paymentB <- B x (1 + 0.016658) - 200, until B <= 0
33 months
Total interest is the sum of every month of interest charged
1,521.02
Total amount paid is the balance plus all the interest5,000 + 1,521.02
6,521.02

Payoff schedule (by month)

Month	Payment	Principal	Interest	Balance
1	200.00	116.71	83.29	4,883
2	200.00	118.65	81.35	4,765
3	200.00	120.63	79.37	4,644
4	200.00	122.64	77.36	4,521
5	200.00	124.68	75.32	4,397
6	200.00	126.76	73.24	4,270
7	200.00	128.87	71.13	4,141
8	200.00	131.02	68.98	4,010
9	200.00	133.20	66.80	3,877
10	200.00	135.42	64.58	3,741
11	200.00	137.67	62.33	3,604
12	200.00	139.97	60.03	3,464

Amounts are in the currency selected above. Early payments are mostly interest; later payments are mostly principal.

Formula

i = \dfrac{\text{APR}}{12}.\ \text{Time: } B \leftarrow B(1+i) - P\text{ until }B\le 0.\ \text{Payment for }n\text{ months: } P = \dfrac{B\,i\,(1+i)^n}{(1+i)^n - 1}

Worked example

A 5,000 balance at 19.99% APR (83.29 first-month interest) with a 200 payment clears in 33 months and about 1,521 in interest. To clear it in 24 months instead, the amortization formula gives a payment near 254 a month, cutting total interest to roughly 1,099.

Two modes: solve for time or solve for the payment

In fixed-payment mode you enter a monthly payment and the calculator counts the months to zero, stepping the balance forward one month at a time. In target-date mode you enter the number of months you want to be debt-free in, and the calculator reverse-solves the standard amortization formula to find the exact payment that clears the balance on schedule. Use the first mode when you know what you can afford, and the second when you have a deadline in mind, such as before an interest-free promotional rate ends.

How the payoff timeline is calculated

Each month, interest is charged on the remaining balance at the monthly rate, which is the APR divided by twelve. Your payment first covers that interest, and whatever is left reduces the principal. The calculator repeats this month after month until the balance reaches zero, counting the months along the way. Because interest is charged on the shrinking balance, the share of each payment going to principal grows over time, which is why the schedule below starts interest-heavy and ends principal-heavy.

Extra payments and the never-pays-off trap

Adding an extra amount to every payment, or a one-time lump such as a tax refund, sends money straight to principal and compounds its effect: a lower balance means less interest next month, which leaves more of the following payment for principal. The calculator reports how much interest those extras save versus the base payment alone. The opposite case is the never-pays-off trap: if your payment is smaller than the interest charged that month, the balance grows rather than shrinks and the debt never clears. This is the danger of making only minimum payments on a high-rate card, so always pay more than the monthly interest.

Avalanche vs snowball when you have several debts

This tool focuses on one debt at a time, but if you are juggling several, two strategies stand out. The avalanche method targets the highest-APR debt first while paying the minimum on the rest, which mathematically minimizes total interest. The snowball method targets the smallest balance first to score quick wins and build momentum. Avalanche saves the most money; snowball can be easier to stick with. Run each of your debts through this calculator to see the numbers, then attack them in your chosen order.

Payoff time and interest on a 5,000 balance at 19.99% APR

Monthly payment	Months to pay off	Total interest	Outcome
80	Never	Infinite	Bad
150	50	2,357	High
200	33	1,521	Moderate
300	20	906	Low
500	12	515	Low

How the monthly payment changes your payoff timeline and total interest.

Frequently asked questions

How do I find the monthly payment needed to be debt-free by a certain date?

Switch the calculator to target-date mode and enter the number of months you want. It reverse-solves the amortization formula, P = B x i x (1+i)^n / ((1+i)^n - 1), to give the exact payment. For a 5,000 balance at 19.99% APR over 24 months, that is about 254 a month.

Why does my debt never get paid off at the minimum payment?

If the payment is less than the interest charged that month, the balance grows instead of shrinking. On a 5,000 balance at 19.99% APR, the first month of interest is about 83, so any payment at or below that makes no progress and the debt never clears.

How much do extra payments save me?

Every extra dollar goes straight to principal, which lowers future interest. On a 5,000 balance at 19.99% APR, paying 300 instead of 200 a month cuts payoff from 33 months to 20 and saves over 600 in interest. The calculator shows your exact saving in the results.

Should I use the avalanche or snowball method for multiple debts?

The avalanche method pays the highest-APR debt first and saves the most interest. The snowball method pays the smallest balance first for quick motivational wins. Avalanche is mathematically cheaper, but the best method is the one you will actually stick with.

Sources

Was this calculator helpful?

Written by Sarah Klein, CFP Certified Financial Planner · Chicago, USA

Fifteen years translating mortgage tables and amortization schedules into decisions that actually help real borrowers.

How we build & check our calculators

This tool provides general information and education, not professional advice. For decisions about your health or finances, consult a qualified professional.