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Free · Highest APR first · Math-optimal

Debt avalanche calculator — highest-APR-first method

The avalanche method attacks debts in descending APR order — mathematically the cheapest path out. See your total interest saved vs the snowball method.

Where avalanche actually wins big · Snowballr Research · /research/debt-snowball-vs-avalanche-1000-scenarios
Mixed credit-card + auto + student profiles save the most
Our 1,000-profile simulation shows avalanche's margin over snowball widens when the credit card APR is 18%+ AND there's a large low-APR debt (student or auto) competing for cash. Across profiles with this composition, avalanche saved 3.7× the median amount vs same-APR-class profiles.
We default the calculator's example to a mixed-debt profile so the avalanche advantage isn't artificially small (single-debt 'avalanche' is just amortization).
Strategy
Choose your payoff method
Your debts
4 debts · Total: $35,800
53% utilization
63% utilization
$200
Applied on top of minimum payments to accelerate the snowball
Debt-free in
3y 11m
Interest paid
$4,815
Total paid back
$40,615
Comparison
Snowball vs Avalanche
❄️ Snowball
Time:3y 11m
Interest:$4,815
🏔️ Avalanche
Time:3y 11m
Interest:$4,730
💡 Avalanche saves you $85 in interest, but snowball gives faster psychological wins.
Payoff order
When each debt disappears
Debt payoff chart with 4 debts. Longest payoff: Student loan in 3y 11mo. Total interest paid across all debts: $4,816.Horizontal bar chart showing months until each debt is fully paid off. Hover for individual debt details.Store credit4moCredit card1y 7moCar loan2y 6moStudent loan3y 11mo0mo9mo19mo28mo38mo47mo

Why avalanche saves more interest

Interest accrues daily on every dollar of debt at each debt's APR. A $5,000 balance at 24% APR generates $1,200/year of interest. A $5,000 balance at 6% generates $300/year. Killing the higher-APR debt first stops the bigger interest stream faster.

On a typical $25,000 debt mix, avalanche saves $600–$2,400 in interest over snowball and finishes 1–4 months sooner. The exact gap depends on how skewed your APRs are.

Avalanche vs snowball — when each wins

ScenarioBetter method
One huge high-APR debt + small low-APR debtsAvalanche
Several small debts of similar APRSnowball (psychological wins)
You've quit debt plans beforeSnowball (momentum matters)
You're a spreadsheet personAvalanche
Debt mix has wide APR spread (5% to 28%)Avalanche (big savings)

Avalanche execution checklist

  1. Sort debts by APR, descending
  2. Pay minimums on every debt every month
  3. Send all extra cash to the top-APR debt
  4. When debt #1 clears, redirect its full payment to debt #2
  5. Continue down the list — never pay any debt below minimum

Debt Avalanche Calculator FAQ

Avalanche vs snowball — which should I use?

Avalanche if you're disciplined and want to save the most money. Snowball if you've struggled to stick with plans before; the quick wins from killing small debts first build momentum. Behavioral economics studies show snowball completers actually have higher debt-payoff rates despite worse math.

Does avalanche always save money vs snowball?

Yes, mathematically — by definition, avalanche minimizes total interest. The gap is small when debts have similar APRs, and large when APRs differ widely (6% vs 28%). For a typical mix the savings is 5–15% of total interest paid.

What if my smallest debt is also my highest APR?

Both methods agree — start there. Snowball and avalanche only diverge when balance and APR rankings conflict. When they align, momentum and math both win at once.

Should I switch from snowball to avalanche mid-plan?

If snowball is working, don't switch. The behavioral gain of momentum outweighs the few hundred dollars of additional interest. If you're stalled and need fresh motivation, recalculate in avalanche order and see if a different next-target feels more energizing.

Does avalanche apply to my mortgage?

Usually no — mortgage APRs (6–7%) are below credit card APRs (20%+). Avalanche says: pay off credit cards first, never touch mortgage extras until unsecured debt is clear. Once unsecured debt is gone, then evaluate mortgage extras vs investing.

What if APRs change during my plan?

Re-rank if a variable-rate debt jumps significantly. Credit card APRs can rise after a missed payment (penalty APR up to 29.99%). Federal student loan rates are fixed; private student loans can be variable. Re-check rankings every 6 months.

Related calculators

Snowball vs avalanche (guide)
Math + behavior comparison.
Debt payoff calculator
Both methods side-by-side.
Snowball method explained (guide)
Step-by-step framework.
Pay off debt vs invest?
When to switch focus.

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