This tool shows how long it will take to pay off what you owe and how much interest you'll pay along the way. List your debts, choose how much extra you can put toward them each month, and the chart will compare two popular ways to pay them down. Then add your income to see how much of it your debt payments take up, and whether it's a good time to start investing.
1Your debts
Add every debt you're carrying. For each one, enter the balance (how much you still owe), the interest rate (the yearly percentage the lender charges you, often shown as APR on your statement), and the minimum payment (the smallest amount you're required to pay each month). Pick a type to fill in a typical rate and see how that debt is usually treated for tax purposes, or choose Other and just enter a rate.
A note on 401k matches: if your employer offers a 401k match, it's often worth contributing enough to get the full match before putting extra money toward debt, since that match is essentially free money that beats most debt interest rates.
This is the extra amount, beyond what your debts require, that you choose to put toward your debts each month. Every debt always gets its own minimum payment: this extra amount is the part you get to choose where to send.
Two ways to order your debts: Snowball pays off your smallest balance first, for quick wins that keep you motivated. Avalanche pays off your highest interest rate first, which usually saves you the most money overall. Either way, once a debt is paid off, its minimum payment rolls onto the next one. The chart below shows both, so you can compare them side by side.
2Your payoff timeline
Each line shows the total you still owe, month by month, if you follow that method. The point where a line reaches $0 is the month you'd be debt-free.
Left side: total balance still owed. Bottom: time from today. Show or hide either line with the checkboxes, and hover or tap the chart to see exact amounts. When both methods give the same result, the lines are drawn slightly apart so you can see both.
3Debt-to-income ratio
How your required monthly debt payments compare to your income, separate from the extra payment you're choosing to make above. This just measures how much of your income is already tied up in debt.
Your total monthly pay before taxes or anything else comes out.
Under 36% is generally considered healthy, 36–49% draws caution, and 50%+ is a red flag by most lenders. These bands come from general mortgage-lending underwriting guidelines, not a single official rule, and actual thresholds vary by lender and loan type.
Is it safe to invest?
Pay It Down is a debt snowball vs. avalanche calculator. List what you owe, add any extra you can pay each month, and it shows when you'd be debt-free and how much interest you'd pay with each method, side by side.
How to use Pay It Down
- Add each debt with its type, balance, interest rate and minimum payment. Typical rates are filled in for each debt type; replace them with yours.
- Enter any extra amount you can pay each month on top of your minimums.
- Compare the snowball and avalanche payoff dates and total interest on the chart, then add your gross monthly income to see your debt-to-income ratio.
How this calculator works
Both methods start the same way: every debt gets its minimum payment every month, so nothing falls behind. The only difference is where your extra money goes.
The debt snowball sends it to your smallest balance first. Clearing a whole debt quickly feels good, and that momentum keeps a lot of people going. The debt avalanche sends it to your highest interest rate first, which usually costs the least, because you're shrinking the debt that grows fastest.
With either method, once a debt is paid off, its minimum payment rolls onto the next target. Your monthly payment power grows as debts disappear. That's where the snowball gets its name.
Behind the scenes, the calculator steps through one month at a time. It adds a month of interest to each balance (the yearly rate divided by 12), pays every minimum, then sends whatever's left to the target debt, for up to 50 years. Your debt-to-income ratio, your required monthly payments divided by your gross monthly income, shows how much of your paycheck debt already claims.
A worked example
Say you have three debts: a $4,000 car loan at 6.4% with a $250 minimum, a $9,000 credit card at 22.2% with a $270 minimum, and a $15,000 student loan at 6.5% with a $170 minimum. You can put an extra $300 a month toward them, and you earn $5,200 a month before taxes.
Both methods get you debt-free in 2 years and 9 months. The snowball clears the car loan first and costs about $4,201 in interest. The avalanche goes after the credit card first and costs about $3,877, a $324 savings.
Your $690 in required minimums is 13.3% of your gross income, comfortably in the healthy range. Raise the extra payment to $400 and the avalanche also finishes a month sooner. (These figures are illustrative, run through this calculator for a made-up borrower.)
Methodology and sources
The model charges interest monthly at one-twelfth of each yearly rate, holds rates steady and assumes every payment arrives on time. Real credit cards usually compute interest daily, and variable rates change, so treat the payoff dates as close estimates.
The typical rates filled in for each debt type are U.S. averages as of September 2026: credit cards from the Federal Reserve's G.19 consumer credit report, mortgages from Freddie Mac's weekly survey, and new federal student loans from the Department of Education. The debt-to-income bands (under 36%, 36% to 49%, 50% and up) are common lending guidelines, not an official rule.
- Consumer Financial Protection Bureau: What is a debt-to-income ratio?
- Federal Reserve G.19 Consumer Credit
- Freddie Mac Primary Mortgage Market Survey
- Federal Student Aid: Interest rates
Last updated: October 2026
Frequently asked questions
Is the debt snowball or the debt avalanche better?
The avalanche usually costs less interest, because it pays down your most expensive debt first. The snowball can still win in real life if quick payoffs keep you motivated. If the gap here is small, pick the one you'll actually stick with.
How much does the debt avalanche save?
Often less than people expect. In the example above, it saved $324 and finished in the same month. The gap grows when your smallest debts carry low rates and your biggest ones carry high rates.
How do I calculate my debt-to-income ratio?
Add up your required monthly debt payments and divide by your gross monthly income, which is your pay before taxes. For example, $690 in minimums on $5,200 a month is 13.3%. Many lenders like to see it under 36%.
Should I pay off debt or invest first?
A common rule of thumb is to pay off high-interest debt, like credit cards, before investing beyond any employer match, because every dollar of interest you avoid is a guaranteed return. Low-interest debt is more of a judgment call.
Why does the calculator say my debt will never be paid off?
That happens when a minimum payment doesn't cover the interest the debt adds each month, so the balance never shrinks. Raise the extra payment, or check that the minimum matches your statement.
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