Debt Payoff Calculator
The Debt Payoff Calculator compares two popular strategies: the Avalanche method (pay off highest interest rate first — minimises total interest) and the Snowball method (pay off smallest balance first — maximises motivation).
Educational estimate. Calculator results are for planning and information only, not financial, tax, medical, legal, or engineering advice. Verify important decisions with official sources or a qualified professional.
Debt Payoff Calculator
Avalanche vs Snowball Method
📐 Formula & Method
Avalanche Method
Mathematically optimal — minimises total interest paid.
Snowball Method
Psychologically powerful — eliminates accounts quickly to build momentum.
📋 How to Use
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Enter your total debt and average interest rate.
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Enter your monthly payment capacity.
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Add any extra payment you can make.
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Compare Avalanche vs Snowball timelines and interest costs.
Avalanche vs Snowball — Which Debt Strategy is Better?
The Avalanche method saves the most money mathematically — by targeting high-interest debt first, you reduce the principal on which interest accrues. On a $15,000 balance at 20% APR, the Avalanche method can save hundreds compared to Snowball.
However, research shows many people stick with the Snowball method longer because quick wins — eliminating a small balance entirely — create motivation. The best method is the one you actually follow through on.
🔬 Methodology & Accuracy
Formula: Uses the standard mathematical formula shown in the Formula & Method section above. All computations run client-side in your browser — no data is sent to our servers.
Data sources: Tax bands, contribution limits and regulatory rates are taken from official US (IRS, SSA) and UK (HMRC, gov.uk) publications for the current tax year, and updated when bands change.
Last reviewed: January 2025 · Accuracy: Results are precise to two decimal places using IEEE-754 double-precision arithmetic. Intended for educational and planning use only.
For informational purposes only. Results are estimates based on the inputs and formulas provided. For financial, tax, medical, or legal decisions, consult a qualified professional. Rates and regulations change — always verify current figures with official sources.