How this debt payoff calculator works
Add every debt you're carrying — balance, interest rate, and minimum payment — along with the total monthly budget you can put toward all of them combined. Choose snowball (smallest balance first) or avalanche (highest rate first), and the calculator runs a full month-by-month payoff schedule: every debt's minimum is paid, and any money left over cascades toward your target debt, then rolls to the next one as each balance clears.
Snowball vs. avalanche — never framed as a wrong choice
Avalanche minimizes total interest by construction — it always sends extra dollars to your most expensive debt first. Snowball usually costs a bit more in interest, but clears your first balance sooner, which is a real, well-documented reason people stick with a debt payoff plan longer. Neither method is "wrong" — this calculator shows you both numbers side by side so you can decide what actually works for you.
What the calculator assumes
Interest compounds monthly (APR ÷ 12) on each balance — a standard simplification versus a card issuer's exact daily periodic rate. The minimum payment model is either the exact number you enter per debt, or an estimate (a percentage of balance plus a dollar floor) if you don't know your card's actual formula — never a live, per-issuer minimum. This is an estimate to help you plan, not financial advice.
Frequently asked questions
What is the debt snowball method?
The snowball method pays minimums on every debt, then puts all extra money toward the SMALLEST balance first, regardless of interest rate. Once that debt is paid off, its payment "snowballs" onto the next-smallest debt. It costs more in interest than avalanche, but clears your first debt faster — a real motivational edge for a lot of people.
What is the debt avalanche method?
The avalanche method pays minimums on every debt, then puts all extra money toward the HIGHEST-interest-rate balance first. Mathematically, this minimizes the total interest you pay across all your debts — it just doesn't always clear an individual debt as quickly as snowball does.
Snowball vs. avalanche — which saves more money?
Avalanche almost always saves more in total interest, since it targets the most expensive debt first. Snowball can still be the better choice if the psychological win of clearing a full balance sooner keeps you consistent — a plan you stick with beats a technically-optimal plan you abandon.
What happens if I only pay the minimum on my credit cards?
You stay in debt far longer and pay far more in interest than the balance itself. On a $5,000 balance at 22.99% APR, paying only the minimum can take close to 20 years and cost more in interest than the original balance — this calculator shows your own numbers for that exact scenario.
How is my minimum payment calculated?
There's no universal formula — issuers vary. A common approximation is the greater of a flat dollar floor (often $25–$35) or roughly 1–2% of the balance plus that month's interest. This calculator lets you enter your card's actual minimum directly, or use that percentage estimate if you don't know it offhand.
Worked examples
Worked example 1
Three cards, avalanche vs. snowball (the O1 case)
A $3,000 card at 14.99%, a $6,000 card at 22.99%, and a $9,000 card at 18.99%, with a $700 monthly budget — a case where the smallest balance is NOT the highest rate, so the two methods genuinely diverge.
Interest saved
$440
Sooner first payoff
7 mo (snowball)
Avalanche saves $440 in interest on these three cards. Snowball still clears its first card 7 months sooner — a real motivational edge if that matters more to you than the extra interest.
Worked example 2
Only pay the minimum — the $5,000 card
A single $5,000 balance at 22.99% APR, paying only the estimated minimum every month, forever.
Only minimum
19y 4mo
Interest cost
$8,489
Paying only the minimum on a $5,000 balance at 22.99% takes 19 years and costs $8,489 in interest — more than the original balance itself.
Worked example 3
Same three cards, snowball order
The same $3,000 / $6,000 / $9,000 cards from example 1, run with snowball instead.
Debt-free in
2y 10mo
Total interest
$5,676
Snowball clears the smallest card first, then the next, until every balance reaches zero in 3 years, paying $5,676 in interest along the way.
Months to pay off by balance and APR, at a flat $200/mo
Months to pay off by balance and APR, at a flat $200/mo
| Balance ↓ / APR → | 15% | 20% | 25% | 30% |
|---|---|---|---|---|
| $2,000 | 11 mo | 1y | 1y | 1y |
| $5,000 | 2y 7mo | 2y 9mo | 3y | 3y 4mo |
| $10,000 | 6y 7mo | 9y 1mo | — | — |
| $15,000 | 18y 8mo | — | — | — |
Single balance, paying a flat $200/mo with no minimum floor — every cell computed live.
Every cell is computed live from lib/debt-payoff.ts at render time — never hand-typed.
What affects the result
Your monthly budget
The single biggest lever — every dollar above your combined minimums shortens the payoff and cuts interest, and cascades to your next debt the moment your target clears.
Which method you choose
Avalanche (highest rate first) minimizes total interest. Snowball (smallest balance first) usually costs a little more but clears your first debt sooner — a real behavioral edge for a lot of people.
Your interest rates
A high-rate card left on minimum-only payments accrues interest fast enough to erase most of your progress on lower-rate balances — this is exactly what avalanche targets first.
How your minimum is modeled
A fixed dollar minimum (from your statement) behaves differently over time than a percent-of-balance estimate, which shrinks as your balance does — switch models to see which matches your actual cards.
A one-time lump sum
A tax refund, bonus, or other windfall applied to your target debt compounds the same way a permanent budget increase does, just for one month — see the "Add a lump sum" What-If chip.
Common mistakes to avoid
- ✗Comparing avalanche and snowball only on interest paid, ignoring that snowball's early win is a real, documented reason people stick with a plan longer than they would otherwise.
- ✗Assuming your card's minimum payment is a fixed formula — issuers vary, and the percent-of-balance estimate this calculator defaults to can differ from your actual statement.
- ✗Treating "debt consolidation" as automatically cheaper — a consolidation loan's rate has to beat your current weighted-average rate, and closing cards can affect your credit utilization and score.
- ✗Forgetting that a windfall (tax refund, bonus) applied as a lump sum toward your target debt is one of the fastest ways to shorten a payoff, cheaper than most people assume.
Practical takeaways
- ✓If you're not sure which method to pick, run both — the numbers above show you exactly what the interest difference costs, in dollars, for your own debts.
- ✓Increasing your monthly budget by even a small, sustainable amount compounds: it shortens the payoff and reduces interest on every debt still open when it kicks in.
- ✓Before paying only the minimum "for now," check what that actually costs in the calculator above — the real number is usually far higher than it feels.
- ✓A lump sum toward your highest-priority debt (whichever method you're using) is one of the highest-leverage single moves you can make.
Key terms
- Debt snowball
- Pay every debt's minimum, then put all extra money toward the SMALLEST balance first, regardless of interest rate. When that debt clears, its payment rolls onto the next-smallest — a behavioral method: it usually costs a bit more in interest than avalanche but clears your first debt sooner.
- Debt avalanche
- Pay every debt's minimum, then put all extra money toward the HIGHEST-interest-rate balance first. This mathematically minimizes total interest paid across all your debts, given every debt's minimum is paid regardless of order.
- Minimum payment
- The smallest amount an issuer requires each month to keep an account current. There's no universal formula — a common approximation is the greater of a flat dollar floor (often $25–$35) or roughly 1–2% of the balance plus that month's interest. Paying only this amount, forever, is the slowest and most expensive way to clear a balance.
- Intra-month rollover
- When your target debt clears mid-month, the leftover from that month's payment doesn't wait until next month — it immediately rolls to the next debt in your payoff order, the same month. This is what makes a payoff schedule converge faster than treating each month's budget as a fixed, un-redirectable amount.
- APR vs. daily periodic rate
- This calculator compounds interest monthly (APR ÷ 12) on each balance — a standard simplification. Card issuers actually use a daily periodic rate (APR ÷ 365) applied to your average daily balance, which can differ slightly from the monthly-compounding estimate here, usually by a small amount.
- "Unpayoffable" budget
- A budget that covers every debt's minimum payment but doesn't exceed the combined interest accruing each month — so the total balance never actually shrinks, no matter how long you wait. Distinct from an infeasible budget, which doesn't even cover the minimums.
More questions answered
Can I switch methods partway through?
Yes — nothing locks you into snowball or avalanche. Use the "Switch method" What-If chip to see exactly how much interest changes if you flip, based on your current debts and budget, then decide.
What if my budget can't even cover my minimums?
The calculator flags this directly and tells you the exact minimum budget needed to cover every debt's minimum payment — that's the floor before any payoff plan can work at all.
Does adding a debt change my results?
Yes — every debt you add is included in that month's minimum-payment total and joins the payoff order (by balance for snowball, by rate for avalanche). Add or remove debts freely; the schedule recomputes live.
Model assumptions & disclosures
Interest compounds monthly, not daily. Every payoff schedule on this page uses APR ÷ 12 applied to each balance once a month — a standard simplification. Card issuers actually use a daily periodic rate (APR ÷ 365) applied to your average daily balance, which can differ slightly from the monthly-compounding estimate used here.
The minimum payment model is an estimate, not your card's real formula. There is no universal minimum-payment rule — issuers vary. The default here is the greater of a $25 floor or roughly 1% of your balance plus that month's interest, and it's fully editable. Enter your card's actual minimum from your statement for the most accurate result; whether you use a fixed or percent-estimated minimum can materially change how long payoff takes.
Snowball's value is behavioral; avalanche's is mathematical. Avalanche minimizes total interest by construction — it always targets the highest-rate balance first. Snowball usually costs a bit more in interest but clears your first debt sooner, which for many people is the difference between sticking with a plan and abandoning it. Neither is presented as the "wrong" choice.
Debt settlement, relief, and bankruptcy are out of scope. This calculator only models paying debts off in full, on your own schedule. It does not compute settlement offers, debt relief programs, or bankruptcy outcomes — those involve legal and credit consequences well beyond a payoff calculator and are best discussed with a licensed credit counselor or attorney.
Not financial advice. This calculator provides illustrative estimates based on the inputs you enter. It does not know your full financial picture, your card issuers' specific policies, or your credit situation. Consult a financial advisor or accredited credit counselor before making decisions based on these figures.