Debt Payoff Calculator
Add your debts, pick snowball or avalanche, and get your payoff order, debt-free date and total interest — with both strategies compared
// Your Debts
// Strategy & Extra Payment
Avalanche: highest interest rate first — always the cheapest route.
// Payoff Order
| Debt | Paid off | Month | Interest paid |
|---|---|---|---|
| 📉 Your payoff plan will appear here | |||
How to Use the Debt Payoff Calculator
List each debt with its current balance, interest rate (APR) and minimum monthly payment. Add any extra amount you can commit each month, then compare the two strategies. The calculator simulates every month: interest accrues on each balance, every debt receives its minimum, and all extra money — plus the minimums freed up by cleared debts — attacks one target debt at a time.
The rollover effect
The engine behind both strategies is the rollover: when a debt dies, its minimum payment doesn't return to your pocket — it joins the attack on the next target. Your total monthly outlay stays constant while the force applied to each remaining debt grows, which is why payoff accelerates toward the end like a snowball rolling downhill.
Snowball vs Avalanche: The Full, Honest Comparison
Built and verified by Andrius R. · Updated June 2026
Every debt payoff plan answers one question: with limited money, which debt gets the extra? The two famous answers — avalanche (highest rate first) and snowball (smallest balance first) — have been argued about for decades. The argument resolves cleanly once you see real numbers and admit what each method is optimizing.
The same three debts, both ways
Credit card $5,000 at 22% (min $125) · car loan $8,000 at 7% (min $250) · personal loan $3,000 at 11% (min $90). Combined minimums: $465/month, plus $200 extra.
| Strategy | First win | Debt-free | Total interest |
|---|---|---|---|
| Avalanche (rate order: 22 → 11 → 7%) | Month 19 | 28 months | ~$2,188 |
| Snowball (size order: 3k → 5k → 8k) | Month 11 | 28 months | ~$2,537 |
| Minimums only (no extra, no rollover) | Month 36 | 45 months | ~$4,614 |
Read the table twice. First reading: avalanche saves ~$349 — real money, always take it if motivation isn't your constraint. Second reading: the gap between the two strategies ($349) is dwarfed by the gap between either strategy and drifting on minimums (~$2,400 and 17 months). The choice of method is the small decision; the decision to attack at all is the big one.
Why avalanche always wins on paper
Interest is rent charged on borrowed money, and the avalanche evicts the most expensive tenant first. Every month a 22% balance survives costs roughly three times what the same balance costs at 7%, so killing high-rate debt early shrinks the total rent bill — a result that holds for any set of balances and rates. The avalanche can only tie the snowball (when the smallest debt also has the highest rate); it can never lose.
Why snowball wins anyway, for many people
Debt payoff is a years-long behavior, not a single calculation — and behavioral research (including analyses of thousands of real repayment records published via Kellogg and HBR researchers) found that people who clear individual accounts early are more likely to finish eliminating their debt. The snowball manufactures exactly that: in the example it delivers its first cleared debt in month 11 versus month 19. If a $349 "motivation fee" is what keeps you attacking for 28 straight months instead of quitting in month 14, it's the best money in the plan. The honest rule: check the gap with this calculator first — when it's small, pick by personality; when your rates span 7% to 29%, the avalanche's edge grows and deserves more weight.
Force multipliers worth stacking on either method
- Balance transfers and consolidation: moving a 22% card balance to a 0% promotional card (typical fee 3–5%) or consolidating into a ~11% personal loan changes the math more than the strategy choice does — model it by editing the rates above, and see the credit card calculator for the fine print.
- Found money goes to the target: tax refunds, bonuses and side income hit hardest as one-off strikes on the current target debt — a single $500 lump in month one of the example saves more interest than it ever will later.
- Stop the refill: no plan survives new spending on the cards being cleared. Freeze, hide or delete the stored numbers; run daily spending on debit until the balance reads zero.
- Don't starve the safety net: keep a small emergency buffer (~$1,000) while attacking — without it, the first surprise bill lands back on the very card you just cleared. The savings guide covers the sequencing.
When neither method is enough
If the calculator shows a payoff measured in decades, or your minimums alone exceed what you earn, the problem isn't strategy selection. Nonprofit credit counselling, debt management plans, and (in genuine insolvency) formal relief options exist precisely for that situation — and reaching for them early preserves far more than waiting does. A calculator can optimize a plan; it can't substitute for one.
// Rollover Power
Cleared minimums roll into the next target automatically — your outlay stays flat while the attack grows.
// Compare First
Toggle both strategies before committing. If the interest gap is small, pick the one you'll stick with.
// One Target
Spreading extra money across all debts feels fair and works worst. Concentrated force wins.
// Watch the Warning
If a payment doesn't cover a debt's monthly interest, the balance grows forever — the calculator flags it.