CalcLibrary

Debt Payoff Calculator

Estimate how long it could take to pay off a debt and how extra payments may reduce interest and shorten the payoff timeline.

Currency
$
%
$
$
Examples

A $15,000 credit card balance at 18.9% APR with $300 minimum payment.

Months to Payoff
100 months
Total Interest Paid
$14,733.15
Total Amount Paid
$29,733.15
Months Saved vs. Minimum Only
0 months
Status
On track

You'll pay 98% of your balance in interest before it's paid off.

Planning estimate only. Real payoff timelines and totals can change with fees, rate changes, taxes, and lender-specific payment rules.

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Examples

How It Works

Formula

It=Bt−1×r12I_t = B_{t-1} \times \frac{r}{12}

Bt=Bt−1+It−PtB_t = B_{t-1} + I_t - P_t

Variables

BtB_t

Balance at end of month t

Bt−1B_{t-1}

Balance at end of the previous month

ItI_t

Interest accrued in month t

PtP_t

Payment made in month t (minimum + extra)

rr

Annual interest rate (decimal)

Enter your current debt balance, annual interest rate, minimum monthly payment, and any extra payment you can make. The calculator simulates the month-by-month payoff, showing how long it takes, how much total interest you will pay, and how many months you save with extra payments compared to minimums only.

Month-by-month simulation, repeated until the balance reaches zero:

  1. Accrue interest on the previous balance: It=Bt−1×r/12I_t = B_{t-1} \times r/12.
  2. Apply the payment, capped so it never exceeds what is owed: Pt=min⁡(Minimum+Extra,  Bt−1+It)P_t = \min(\text{Minimum} + \text{Extra},\; B_{t-1} + I_t).
  3. Update the balance: Bt=Bt−1+It−PtB_t = B_{t-1} + I_t - P_t.
  4. Repeat until Bt=0B_t = 0.

Months saved is the difference between the minimum-only run and the run with extra payments. If the payment never exceeds the monthly interest, the balance grows and the calculator reports that the debt cannot be paid off under those terms.

Frequently Asked Questions

01How are the interest savings calculated?
The calculator simulates your payoff month by month. Each month, interest accrues on the remaining balance, your payment reduces the balance, and the process repeats. With extra payments, the balance drops faster so less interest accumulates. The savings are the difference between the two scenarios.
02What if my minimum payment doesn't cover the monthly interest?
If your payment does not cover the monthly interest, the balance can grow instead of shrink. This is called negative amortization. The calculator marks that case as not payable under the current terms.
03Should I pay extra on my debt or invest instead?
Paying down high-interest debt can improve your financial foundation because the interest you avoid may exceed returns available from many investments. This calculator does not decide for you; it only shows the debt-payoff side of that tradeoff.
04What is the avalanche vs. snowball method?
The highest-interest-rate method puts extra payments toward the most expensive debt first. The snowball method puts them toward the smallest balance first. CFPB notes the highest-interest-rate method can eliminate the most costly debt first, while the snowball method can create quicker progress and motivation for some people.
05Does this calculator handle multiple debts?
This calculator models one debt at a time. For multiple debts, run each balance separately. If you use the highest-interest-rate method, direct extra payments to the highest-rate debt first; if you use a snowball plan, focus on the smallest balance first.

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