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Debt Payoff Calculator
Avalanche saves the most interest; snowball keeps you motivated. This debt payoff calculator runs both methods on your real debts side by side, showing your debt-free date, total interest, and the exact dollars and months one approach saves over the other.
See how this works on $18,700 across three debts — 3 real examples
Debt-free date (avalanche)
—
Time to debt-free
—
Total interest
$0
Total paid
$0
Avalanche vs snowball, on your debts
—
Avalanche — highest APR first
- Debt-free
- —
- Total interest
- $0
Snowball — smallest balance first
- Debt-free
- —
- Total interest
- $0
Payoff order
Combined balance over time
Add a debt to get started
Enter at least one debt with a balance above $0 — a balance, APR and minimum payment — and your avalanche-vs-snowball payoff plan appears here.
Your payoff plan, month by monthCombined balance and cumulative interest for the selected method
| Month | Date | Combined balance | Interest to date | Paid to date |
|---|
How your debt-free date and interest savings are calculated
This calculator simulates your debts one month at a time — no shortcut formula — so the payoff order and rollover are modeled exactly:
each month, for every open debt:
interest = balance × APR / 1200
pay each debt its minimum, then
pool = extra + freed minimums (+ lump in its month)
pool → target debt (avalanche: highest APR · snowball: smallest balance)
Every open debt accrues one month of interest, each is paid its minimum (capped at its balance), and the leftover attack pool — your extra payment plus any minimums freed by already-cleared debts, plus a one-time lump in its chosen month — is thrown entirely at a single target debt. That target is the highest-APR debt under the avalanche method and the smallest-balance debt under the snowball method; as each debt hits zero, its freed payment cascades to the next target.
The debt-free date is the month the last balance reaches zero. Interest saved is the difference in total interest between paying your minimums only and paying with your extra amount, and the avalanche-vs-snowball delta is simply the difference in total interest and months between the two methods run on the same debts.
Assumptions: APRs and minimum payments are fixed, interest compounds monthly, and the first payment lands one month from today. If a debt’s minimum is smaller than its monthly interest and the pool never reaches it, that debt can never be retired — it is flagged by name rather than looped forever.
Three debts, two orders of attack
A credit card, a store card and a car loan — $18,700 at three very different rates. The same $200 extra, aimed two ways.
Rollover only: $515 held level
to debt-free51 months
- Keeping the total at $515 as each debt clears pays everything off in 51 months.
- Interest comes to $7,106 across the three debts.
- The car loan exits first at month 39; the 24.99% card survives to the end.
Rolling freed payments forward already beats plain minimums — the extra $200 is the next gear.
Load this example (opens in a new tab)The extra $200 aimed at 24.99%
to debt-free31 months
- The credit card — the priciest debt — falls first, at month 23.
- The clock shortens by 20 months and interest drops to $3,213.
- Against the no-extra plan, that is $3,893 of interest that never gets charged.
Highest rate first is the arithmetic optimum: least interest for the same monthly outlay.
Load this example (opens in a new tab)The same $200, smallest debt first
to debt-free31 months
- The $1,200 store card is gone by month six — one bill disappears almost immediately.
- Interest totals $3,369, exactly $156 more than avalanche.
- Both orders reach zero in the same 31 months; only the route differs.
Snowball costs $156 more and lands its first win 17 months sooner — momentum, priced.
Load this example (opens in a new tab)Illustrations only, not financial advice. Your own rate, taxes and insurance will differ — check with a qualified financial advisor before acting on any of this.
Getting debt-free, in plain English
- Avalanche is cheapest, snowball is stickiest. Highest-APR-first wins on math; smallest-balance-first wins on motivation. This debt free date calculator shows both so you pick with the real numbers, not a rule of thumb.
- The rollover is the whole trick. When a debt is gone, its payment doesn’t vanish — it piles onto the next debt, so your last debts fall dramatically faster than your first.
- Extra dollars go straight to principal. Anything above the minimum skips future interest entirely, which is why an extra $100–$200 a month can erase years.
- Watch the minimum-payment trap. If a card’s minimum doesn’t cover its interest, the balance climbs forever — raise that payment first before optimizing order.
- Order matters less than consistency. On most debt mixes avalanche and snowball finish within a few months and a few hundred dollars of each other; the plan you stick with beats the “optimal” one you abandon.
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Frequently asked questions
What is the difference between the debt avalanche and debt snowball methods?
Both methods pay every debt its minimum, then throw all spare cash at one target debt and roll each freed-up payment into the next. The debt avalanche calculator attacks the highest-APR debt first, which mathematically pays the least total interest. The debt snowball calculator attacks the smallest balance first, so you clear whole debts sooner for quicker motivation. This tool runs both on your exact numbers and shows the interest and time difference so you can choose with eyes open.
Which debt should I pay off first?
If you want the lowest total cost, pay the debt with the highest interest rate first (avalanche). If you want visible wins to stay motivated, pay the smallest balance first (snowball). On typical debt mixes the avalanche saves a few hundred to a couple of thousand dollars, but the gap is often small — the best method is the one you will actually stick with. Toggle the two above and compare the exact numbers for your debts.
When will I be completely debt-free?
This debt free date calculator simulates every month — accruing interest, paying minimums, and applying your extra payment and any one-time lump sum to the target debt — until every balance hits zero. The headline date is your debt-free month for the method you selected. Change the extra-payment amount and the date moves in real time.
How much will extra payments speed up my payoff?
A lot more than most people expect, because every extra dollar goes straight to principal and stops future interest. Adding even $100–$200 a month on top of your minimums can shave years off the plan and save thousands in interest. Enter your extra monthly amount above and the debt-free date, interest total, and savings callout update instantly.
Does rolling each finished payment into the next debt really make a difference?
Yes — that roll-over is the engine behind both methods. When a debt is paid off, its minimum payment does not disappear; it cascades onto the next target debt on top of your extra payment, so your attack pool grows every time a debt clears. That snowball (or avalanche) rollover is why the last debts fall so much faster than the first.
What if a debt never gets paid off?
If a card’s minimum payment is smaller than the interest it accrues each month, the balance grows instead of shrinks and it can never be retired on the minimum alone. When that happens this calculator flags the specific debt so you know to raise its payment or direct your extra dollars there. Increasing that one minimum above the monthly interest is usually all it takes to make the whole plan solvable.
Disclaimer: these calculators are educational tools, not financial advice. They model your inputs with published formulas, but they cannot know your full situation — for decisions with real stakes, talk to a qualified professional. Formulas and defaults last reviewed .