Enter balance, rate and monthly payment to see when you'll be debt-free and how much interest you'll pay.
n = ln(P / (P − B·r)) / ln(1 + r), where B = balance, r = monthly rate, P = monthly payment.
$8,000 at 22% APR paying $300/month → about 33 months and roughly $1,900 in interest.
A debt payoff calculator turns a vague sense of dread into a concrete timeline. A well-built calculator turns a topic that usually requires spreadsheets, formulas, or expert guidance into a single input form with an instant, trustworthy answer. That matters because most people making a decision — a budget, a purchase, a health goal, a homework problem — do not want to install software or open a textbook. They want a clear number and a short explanation of where it came from, and they want it to load on their phone in a second.
Anyone carrying a credit-card balance, a personal loan, or a stubborn line of credit can use this tool. Different visitors arrive here with very different backgrounds. Some are professionals double-checking a value they already estimated in their head. Others are complete beginners who have never seen the underlying formula before. The tool above is designed so both groups can succeed on the first try: defaults reflect realistic real-world inputs, labels are written in plain English, and the result panel highlights the primary number in a large, glanceable format while keeping supporting figures visible for context.
Interest on high-APR debt compounds against you the way investment returns compound for you. Understanding the "why" behind a calculation is what turns a one-off answer into a lasting mental model. This is why every calculator on CalcCosmos publishes the exact formula it uses and walks through a worked example with real numbers. When you can see that a percentage change is nothing more than the difference divided by the starting value, or that a monthly loan payment is a rearranged annuity formula, you gain a portable skill you can reuse anywhere — on a napkin, in a job interview, or with a friend who needs help.
Enter the total balance, the annual percentage rate on the account, and the payment you can consistently make each month. Using the tool above is intentionally straightforward. Enter your values, and the result updates instantly — there is no submit button, no loading spinner, and no page reload. When you're happy with the answer, tap "Copy" to place the result on your clipboard for pasting into a message, a spreadsheet, or a form. Tap "Share" to send it to a friend using your device's native share sheet, which falls back to copying a formatted summary when native sharing is unavailable. All of the math runs directly in your browser, so nothing you enter is transmitted or stored on our servers.
Attack the highest-APR balance first (the avalanche method) or the smallest balance first for motivational wins (the snowball method). A few small habits will make the tool more useful over time. First, treat the default values as a sanity check: if your inputs produce a result that is dramatically different from the default, verify that you entered the right units. Second, if the calculator supports multiple modes, try each one — you often learn something new about the problem simply by comparing how the same variables interact under different assumptions. Third, bookmark the tools you return to often; each calculator lives at a permanent URL that will not change.
Combine the debt payoff calculator with our savings and simple-interest tools to see the total cost of debt versus building emergency savings. CalcCosmos exists to give you the fastest possible path from question to trustworthy answer. If a calculation you rely on is missing from our library, or if you'd like to see additional inputs, edge-case handling, or worked examples added to this page, we want to hear about it. New calculators launch every week based on what people ask us for, and every existing tool is refined based on real user feedback. Thank you for choosing CalcCosmos — we hope this calculator saves you time today and teaches you something you can use tomorrow.
Avalanche saves more money; snowball produces more early wins. The best method is the one you'll stick with.
Keep a small emergency buffer, then aggressively pay down anything above ~7% APR.
Yes, especially by lowering credit utilization on revolving accounts.
Estimate the monthly payment and total interest for any fixed-rate loan.
Estimate your monthly car payment and total loan cost from price, down payment, rate and term.
Compute simple interest on a loan, note or savings vehicle with I = P × r × t.
Project the growth of a savings account with regular deposits and interest.