📖 Overview
This calculator runs both strategies under the same budget to show true timeline and interest differences.
It is designed for practical debt planning where you need a clear tradeoff between speed behavior and cost.
🧪 Example Scenarios
Use these default and higher-pressure example inputs to explore how sensitive this calculator is before using your real numbers.
| Input | Base Case | Higher Pressure Case |
|---|---|---|
| Debt A Balance ($) | 6,800 | 7,820 |
| Debt A APR (%) | 24 | 28.8 |
| Debt B Balance ($) | 3,200 | 3,680 |
| Debt B APR (%) | 9 | 10.8 |
| Monthly Debt Budget ($) | 500 | 575 |
⚙️ How It Works
Simulates two-debt payoff outcomes under avalanche and snowball ordering to compare timeline and interest cost under one fixed monthly budget.
The Formula
Each month: add interest, apply payment by strategy order (highest APR first vs lowest balance first).
| Debt A/B Balance | Current principal balances for two debts |
| Debt A/B APR | Annual rates converted to monthly interest |
| Monthly Budget | Total monthly payment capacity across both debts |
💡This calculator is scenario-based. Better input quality leads to better decision quality.
⚠️If monthly budget is below monthly interest accrual, neither strategy amortizes principal. Increase budget or reduce APR.
Quick Reference
| Setup | Avalanche Outcome | Snowball Outcome |
|---|---|---|
| A:$6k@24%, B:$3k@9%, $450/mo | Faster and lower interest | Usually slower, higher interest |
| A:$2k@18%, B:$1.8k@17%, $300/mo | Near tie | Near tie |
| A:$1.2k@19%, B:$6k@7%, $500/mo | Lower interest | May feel faster early on balance count |
When To Use This
- Use this tool when you need a fast decision during active planning or execution.
- Use this before committing money, time, or tradeoffs that are hard to reverse.
- Use this to compare options using the same assumptions across scenarios.
Edge Cases To Watch
- Results can be misleading if key inputs are missing, stale, or unrealistic.
- Very small or very large values may amplify rounding effects and interpretation risk.
- If assumptions change mid-decision, recalculate before acting.
Practical Tips
💡 Use this as finance math baseline, then layer behavioral constraints intentionally.
💡 If motivation helps consistency, test snowball with higher realistic payment budget.
💡 Re-run when APR changes or debt consolidation is available.
Frequently Asked Questions
❓ Why can avalanche save interest?
Paying highest APR first reduces expensive interest accrual sooner.
❓ Is snowball ever better?
It can improve adherence for some people; if it increases payments materially, total outcome may improve.