Where every payment actually goes
Each month your lender charges interest on the balance you still owe; whatever you pay beyond that charge is the only part that chips away at the debt itself. That single gap — payment minus this month's interest — decides how fast you reach zero. Raise the payment and the gap widens, so principal falls faster and next month's interest is smaller, compounding the benefit in your favour. The calculator above traces that month-by-month so you can see a payoff date and a total interest figure for any balance, APR, and payment.
Clearing a $12,000 card at 22% APR on $350 a month
Carrying a $12,000 credit-card balance at 22% APR and paying a fixed $350 each month, the monthly rate is 22% ÷ 12 = 1.833%. The first month's interest alone is about $220, so only ~$130 of that first $350 touches the principal. Held steady, the balance clears in 55 months (just under 4½ years) and costs roughly $7,081 in interest on top of the $12,000 borrowed. Nudge the payment to $450 and the payoff drops below 40 months — proof of how sharply the timeline responds to the payment size.
Debt Payoff Strategies
Avalanche Method (highest interest first)
List all your debts and direct any extra money to the one with the highest APR while paying minimums on the rest. Once that debt is gone, roll its payment into the next highest-rate debt. This approach is mathematically optimal — it minimizes the total interest you pay over the life of your debts.
Snowball Method (smallest balance first)
Target the debt with the smallest balance first regardless of interest rate. When it's paid off, roll that freed-up payment to the next smallest debt. You may pay slightly more interest overall, but the quick wins provide psychological momentum that many people find easier to sustain.
Extra Payments
Even a modest increase in your monthly payment has an outsized effect. On a $5,000 balance at 18% APR, raising your payment from $100 to $150 cuts the payoff time from 94 months to 47 months — and saves roughly $2,300 in interest. Use the Fixed Payment mode above to test different payment scenarios instantly.
Bi-Weekly Payments
Making half your monthly payment every two weeks results in 26 half-payments per year — the equivalent of 13 full monthly payments instead of 12. That one extra payment per year can shave months or even years off a long-term debt.
How the Debt Payoff Calculation Works
This calculator uses standard amortization math. For the Fixed Payment mode, the number of months is calculated as:
months = −log(1 − r × balance / payment) / log(1 + r)
where r is the monthly interest rate (APR ÷ 12 ÷ 100). For the Fixed Timeline mode, the required monthly payment is:
payment = balance × r / (1 − (1 + r)^(−months))
Each row in the payoff table applies your payment to interest first (balance × r), then the remainder reduces your principal. This matches how virtually all consumer debt — credit cards, personal loans, auto loans — is actually calculated by lenders.
Where a real payoff plan gets messy
This schedule assumes a single debt, a fixed payment made on time every month, and an APR that never moves — convenient for planning, but rarely true for real revolving debt. It does not model a variable rate that resets when the Federal Reserve shifts, late or annual fees, a penalty APR triggered by a missed payment, or new spending added to the same card. It also handles one balance at a time, so it cannot order multiple debts for you the way an avalanche or snowball plan would. Treat the payoff date as a best-case target under steady conditions, and rebuild it whenever your rate, balance, or payment changes.
What people ask about paying off debt
How can I pay off debt faster?
The most effective ways to pay off debt faster are: (1) Pay more than the minimum each month — even small extra payments dramatically reduce total interest. (2) Use the avalanche method — direct extra payments to the highest-APR debt first to minimize interest. (3) Use the snowball method — pay off the smallest balance first to build momentum. (4) Make bi-weekly payments instead of monthly, resulting in one extra full payment per year.
What is the avalanche vs snowball debt payoff method?
The avalanche method targets the highest-interest debt first while paying minimums on all others. This minimizes total interest paid and is mathematically optimal. The snowball method targets the smallest balance first regardless of interest rate. Paying off small debts quickly provides psychological wins and motivation, which can help you stay on track even if you pay slightly more interest overall.
How do you calculate debt payoff time?
To calculate how many months it takes to pay off a debt, use the formula: months = −log(1 − (r × balance / payment)) / log(1 + r), where r is the monthly interest rate (APR divided by 12 then divided by 100). For example, a $5,000 balance at 18% APR with $150/month payment takes about 47 months and costs roughly $1,984 in interest.