Debt Payoff Calculator
Find out when you'll be debt-free and how much interest you'll pay.
Results update as you type.
This calculator is for illustrative purposes only. Actual rates, fees and terms vary by lender. Consult a qualified financial adviser before making borrowing decisions.
How it works
A debt payoff calculator runs a month-by-month simulation of your debt balance to determine exactly when you will reach zero and how much interest you will pay along the way. Each month, interest accrues on the outstanding balance at your annual percentage rate divided by twelve. Your payment first covers that interest, and whatever remains reduces the principal. Because the balance falls a little each month, interest charges slowly shrink — but only if you pay more than the minimum. The minimum payment trap is precisely why this debt payoff calculator matters: credit cards and revolving debt often set minimums low enough that a significant portion of each payment is consumed by interest, leaving only a fraction for principal. Carrying a $10,000 balance at 20% APR and making only the minimum payment can take over 20 years and cost more than double the original balance in interest. Adding even a modest extra payment each month — $50 or $100 — compresses the payoff timeline dramatically and saves a disproportionate amount in interest, because every dollar of principal paid today eliminates future interest on that dollar for every remaining month of the loan. Use the extra payment field to run scenarios and find the sweet spot between cash flow and speed.
Iterative amortization: interest = balance × (APR/12); balance -= (payment − interest) each month
Each period, interest due equals the current balance multiplied by the monthly rate (APR ÷ 12). The payment reduces the balance by the payment amount minus interest charged. The calculator iterates this until the balance reaches zero, counting the months elapsed and summing all interest paid. Comparing totals with and without the extra payment reveals the interest saved and the months eliminated.
Source:Standard loan amortization
We review all our tools from time to time to ensure accuracy.
Worked example
How to use this calculator
- 1
Enter your values
Enter total debt balance, average apr and minimum monthly payment.
- 2
Adjust the options
Adjust extra monthly payment if they apply — sensible defaults are already set.
- 3
Read your result
Months to payoff updates instantly as you type — no button to press.
Frequently asked questions
What is the debt avalanche vs snowball method?
The avalanche method directs extra payments to the debt with the highest interest rate first, minimizing total interest paid — the mathematically optimal approach. The snowball method pays off the smallest balance first regardless of rate, generating quick wins that many people find motivating. Research shows the snowball method leads to better completion rates for some personalities because early payoffs sustain momentum. Choose avalanche for maximum savings, snowball if you need psychological fuel to stay on track.
How much faster do extra payments speed up payoff?
The effect is nonlinear and front-loaded — extra dollars applied early in a loan's life eliminate more future interest than the same dollars applied later, because they prevent interest from accruing on a higher balance for a longer period. On a high-rate credit card, an extra $100 per month can cut years from the payoff timeline and save thousands in interest. The higher the APR, the more powerful each additional dollar becomes. Use the calculator's extra payment field to quantify the impact for your specific balance and rate.
Should I pay off debt or invest?
Compare the guaranteed after-tax return of paying off debt — equal to the debt's APR — against the expected after-tax return of investing. High-rate consumer debt (credit cards at 18–25%) almost always beats investing, since markets average roughly 7–10% long-run and carry risk. Moderate-rate debt (6–10% personal loans) is a judgment call. Low-rate debt (under 5%, especially mortgage interest) is often outpaced by investing, especially inside tax-advantaged accounts.
What is a good debt-to-income ratio?
Lenders evaluate two DTI figures. The front-end ratio divides your housing costs by gross monthly income; conventional mortgage guidelines target under 28%. The back-end ratio adds all monthly debt payments and targets under 36–43% depending on the loan type. For personal financial health, keeping total recurring debt payments below 20% of take-home pay leaves room for savings and unexpected expenses. DTI above 40% is a warning sign that debt is crowding out financial flexibility.
Does paying off debt hurt your credit score?
Generally no — paying off installment loans might cause a tiny temporary dip because it closes an account and reduces credit mix, but the net effect of eliminating the payment is positive. Paying off or reducing credit card balances improves your credit utilization ratio, which is the second most influential factor in FICO scoring after payment history. The utilization gain from paying down revolving debt almost always outweighs any mix-of-credit effect from closing accounts.