Monthly amortization
Each month we apply interest to every debt at APR ÷ 12, then apply your payments. For example, a 24% APR is treated as 2% per month. This is standard credit-card amortization.
Payment order
- Avalanche: extra money goes to the highest-APR debt first.
- Snowball: extra money goes to the smallest-balance debt first.
In both cases we pay every debt's minimum first, then apply the remaining budget to the target debt. When a debt reaches zero, its payment "rolls over" to the next target — the total monthly outlay stays constant until you're debt-free.
Interest saved
"Interest saved" compares your plan against paying only the minimums with no rollover — the slowest realistic baseline (the "minimum payment trap"). The difference in total interest is what your extra payments and strategy save you.
Assumptions & limitations
- Minimum payments are treated as fixed. Real lenders often recalculate the minimum as your balance falls, which would slightly lengthen a minimum-only payoff.
- APRs are assumed constant. Promotional or variable rates aren't modeled.
- We don't model fees, penalty APRs, or missed payments.
- Results are estimates to guide decisions, not a guarantee from any lender.
Data privacy
Everything is computed client-side. Your balances and APRs never leave your browser and are only stored locally on your device so you don't lose your work. See our privacy policy.