Debt Payoff Calculator: See Your Debt-Free Date

Built by SimpleFinances — where users are managing over $500K in real debt with the same payoff logic.

How this debt payoff calculator works

The calculator runs a month-by-month simulation of your actual payoff, the same way an amortization schedule works. Each month it adds interest to every balance (the APR divided by twelve), pays every debt its minimum, and puts your extra amount — plus the minimum payment of every debt you've already finished — toward one target debt. That rollover is the engine of both methods: as each debt disappears, its payment doesn't go back into your pocket, it joins the attack on the next debt. The only difference between the two methods is which debt gets targeted first.

Snowball vs avalanche: which should you pick?

Avalanche (highest interest rate first) is the mathematically optimal order — every dollar of extra payment kills the most expensive debt first, so you always pay the least total interest. Snowball (smallest balance first) usually costs somewhat more in interest, but it clears entire debts faster at the start — and behavioral research on debt repayment consistently finds that those early completed accounts are what keep people going. The honest answer: run both in the calculator above and look at the difference. If avalanche saves you a trivial amount — and for many real debt mixes it's smaller than people expect — take the snowball's momentum. If the gap is hundreds or thousands (which happens when a big high-APR balance sits in the middle of your list), the math is worth the patience. The best method is the one you'll actually sustain until the balance says zero.

A worked example with rounded numbers

Take the calculator's starting numbers: a $3,500 credit card at 24.99% (minimum $90), a $9,000 car loan at 6.5% ($280), and a $12,000 student loan at 5% ($150) — with $200 extra each month. Under the snowball, the credit card is the first target because it's the smallest balance; it happens to also be the highest rate, so snowball and avalanche start identically here — a common situation, and the reason the two methods often land closer than the debate suggests. The card takes the $90 minimum plus the $200 extra; when it's gone, $290 a month rolls onto the next target, then the whole combined payment finishes the last loan. The calculator does exactly this arithmetic for your real numbers, to the month.

Where does the "extra" money come from?

The extra payment is the whole game — at $0 extra, minimum payments on a big credit card balance can run for a decade or more. The most reliable place people find extra money isn't heroic frugality; it's spending they'd forgotten they had. Recurring charges are the usual suspects: in one survey, consumers guessed they spent $86 a month on subscriptions when the actual average was $219.¹ Before deciding your extra payment is $50, it's worth an hour with our forgotten-subscriptions guide — or letting the app's subscription finder do the hour for you. Cancelling $60 of unused subscriptions converts directly into $60 of extra payment, every month, forever.

The mistakes that quietly slow payoff down

• Not rolling finished payments forward. When a debt dies, its minimum payment must join the attack on the next one. Letting it drift back into spending is the most common leak.
• Paying extra across all debts at once. Spreading $200 across five debts feels balanced but finishes nothing; concentration is what makes both methods work.
• Ignoring the credit card while it compounds. A 25% APR balance grows faster than most investments earn. High-rate revolving debt almost always deserves priority over everything except an emergency fund floor.
• Not knowing the real balances. Payoff plans built on guessed numbers drift within a month. Pull the actual balances and APRs from your statements — or connect your accounts and let them stay current automatically.