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Calculate Debt Payoff: Avalanche vs Snowball

Discover your exact debt-free date and see how much time and interest you save by adding extra monthly payments.

• Verified Financial Math • Zero Telemetry / 100% Private • Instant Client-Side Computation

Interactive Debt Payoff Calculator

How quickly can I pay off my debt?

Ready to Compute

Enter your financial parameters below to generate an instant, 100% deterministic breakdown with sensitivity analysis and scenario comparison.

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Mathematical Formulation & Methodology

Decidely executes pure deterministic client-side mathematics. Unlike probabilistic AI models that guess numerical results, every calculation is calculated using standard financial accounting equations:

N = -ln(1 - (B × r / PMT)) ÷ ln(1 + r), where B is balance, r is monthly rate, and PMT is monthly payment amount.

Baseline Assumptions & Standards

  • No new charges or purchases are added to the existing balance
  • Interest rate remains constant throughout payoff period
  • Payments applied directly toward outstanding principal and accrued monthly interest

Worked Example: Paying off $15,000 credit card balance at 19.99% APR

Comparing minimum payments ($350/mo) versus adding an extra $150/mo ($500/mo total).

Example Inputs

Balance $15,000
APR 19.99%
Min Payment $350
Extra Payment $150

Calculated Output

Time to Debt-Free 3.2 years (vs 6.4 yrs)
Interest Saved $6,180
Total Saved $6,180
Key Financial Takeaway:

Adding just $150/month cuts payoff time in half and keeps more than $6,000 in your pocket.

Frequently Asked Questions

Should I use the Debt Avalanche or Debt Snowball method?

The Debt Avalanche (paying highest-interest debt first) saves the most money mathematically. The Debt Snowball (paying smallest balance first) provides quick psychological wins to maintain motivation.

What happens if I only pay the minimum monthly balance?

Credit card minimum payments are structured to pay mostly interest and only 1–2% principal, often trapping borrowers in 15 to 30 years of repayment on modest debts.

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