Debt Payoff Calculator
Calculate how long it takes to pay off debt and total interest paid. See your debt-free date based on balance, interest rate, and monthly payment.
$
%
$
Months to Pay Off
—
Years to Pay Off —
Total Interest Paid —
Total Amount Paid —
Minimum Payment (Interest Only) —
How to Use This Calculator
- Enter your Current Balance — the total amount owed.
- Enter the Annual Interest Rate (APR) — check your statement or account portal.
- Enter your Monthly Payment — must be higher than the interest-only minimum.
- See how many Months until you are debt-free and Total Interest Paid.
Formula
Months to Pay Off:
n = −log(1 − (r × P) / M) / log(1 + r)
- P = Current balance, r = Monthly rate, M = Monthly payment
Total Interest = Total Paid − Original Balance
Example
Example: $15,000 balance, 18% APR, $400/month payment.
- Months to Pay Off: 50 months (4.2 years)
- Total Paid: $19,765
- Total Interest: $4,765
- Interest-only minimum: $225/month (never pays off!)
Frequently Asked Questions
- Debt avalanche: pay off highest-interest debt first (saves the most money). Debt snowball: pay off smallest balance first (provides psychological wins). Avalanche is mathematically optimal; snowball works better for motivation.
- Even small extra payments make a big difference. On a $15,000 debt at 18% APR, paying $400/month vs the minimum ($225) saves thousands in interest and years off repayment time.
- Debt consolidation makes sense if you can get a lower interest rate. Moving $15,000 from 20% credit card debt to a 10% personal loan cuts the interest cost roughly in half. Check for origination fees.
- A missed payment can trigger a penalty APR (often 29.99%), damage your credit score, and add late fees. If you miss a payment, make it up as quickly as possible and contact your lender to request fee waivers.
- Lenders prefer a debt-to-income (DTI) ratio below 36%. Your DTI = total monthly debt payments ÷ gross monthly income. High DTI makes it harder to qualify for loans and signals financial stress.