Debt Payoff Calculator

Before you calculate

Use this calculator when you want to compare how entered balances, rates, scheduled payments, and extra-payment timing affect a multi-debt payoff estimate. Use Fixed Payment Credit Card Payoff for one card with one fixed payment, Credit Card Payment Plan for fixed, minimum-percent, or target-time card modes, DTI when recurring payments need to be compared with income, Budget when the whole monthly cash-flow picture matters, Payment or Loan Payment for installment-loan math, APR when fees and legal disclosure rates matter, and CFPB, FTC, lender, servicer, tax, credit-reporting, legal, debt-counseling, or local regulatory sources for account-specific debt-relief, collection, settlement, hardship, payment-allocation, bankruptcy, tax, legal, regulated-advice, or jurisdiction-specific questions.

Formula summary

The app first keeps only debt rows with a positive balance and sums those balances as starting debt. It records the original scheduled-payment total across active debts. The avalanche order sorts active debts by highest annual rate first, using the smaller starting balance as the tie-breaker. Each month, the app adds interest to every active debt using rate / 100 / 12, then applies that debt's scheduled payment. The remaining budget equals the scheduled-payment budget plus extraMonthlyPayment, plus extraYearlyPayment every 12th month, plus the one-time payment only in its selected month. If fixed total monthly payment is Yes, the original scheduled-payment total stays available after a debt is paid off; if it is No, scheduled payments decline to the still-active debts. Any remaining budget targets the highest-rate active debt until all balances reach zero or the 1200-month safety cap is reached.

Worked example

Example: fixed-total rollover versus declining payments

With the default inputs, the calculator starts with $53,000.00 across a $8,000.00 credit card at 21.99 percent, a $12,000.00 personal loan at 11.5 percent, an $18,000.00 auto loan at 7.25 percent, and a $15,000.00 student loan at 5.5 percent. Scheduled payments total $1,155.00 per month, extra monthly payment is $300.00, extra yearly payment is $1,000.00, and a $2,500.00 one-time payment is applied in month 6. With fixed total monthly payment set to Yes, the app estimates 38 months, 3 years and 2 months, $59,978.88 total paid, $6,978.88 total interest, the credit card paid first in month 12, and the student loan paid last. With the same four debts but no extras and fixed total monthly payment set to No, the estimate stretches to 104 months, 8 years and 8 months, $67,070.42 total paid, and $14,070.42 interest. Internal validation also covers a three-card-style avalanche case and a zero-rate-plus-low-rate case; the public copy uses neutral independent comparator wording and does not publish named comparator references.

The examples show how rollover and extra-payment timing can change a mechanical payoff schedule. They are not creditor payoff quotes, minimum-payment instructions, debt-settlement advice, credit-counseling recommendations, collection-negotiation plans, legal guidance, bankruptcy guidance, tax guidance, credit-score forecasts, or recommendations to use a particular payoff method.

Assumptions

• Debt rows are planning rows, not creditor records. The type label helps organize the estimate, but the calculator does not load real balances, statements, due dates, minimum-payment formulas, credit-card APR buckets, promotional terms, hardship plans, servicer rules, or collection status.
• Scheduled payments are applied to each active debt before the extra-payment budget is aimed at the highest-rate active debt. The model assumes the entered scheduled payments are allowed and made on time, and it excludes late fees, returned-payment fees, over-limit fees, prepayment penalties, new borrowing, new card spending, settlement offers, consolidation-loan costs, credit-counseling plan fees, tax effects, credit-reporting changes, lawsuits, garnishment, bankruptcy, and legal outcomes.
• Scoped independent comparator checks pass for overlapping multi-debt avalanche fixtures, with named evidence kept in internal validation files only. CFPB debt collection, debt-negotiation, credit-counseling, and credit-card interest materials, FTC debt guidance, Regulation Z payment-allocation rules, lender or servicer agreements, tax authorities, legal sources, credit-reporting sources, debt-counseling providers, and local regulators are needed before making real collection, settlement, payment-allocation, fee, hardship, default, forgiven-debt tax, credit-reporting, legal, regulated-advice, or jurisdiction-specific claims. Results are educational estimates, not financial, tax, legal, lending, credit, debt-counseling, regulatory, or personalised advice.

Common mistakes to avoid

• Entering only extra payments and leaving scheduled payments at zero. The app applies each debt's scheduled payment first, so missing scheduled payments can make the payoff estimate much slower or less realistic.
• Reading fixed total monthly payment as a creditor rule. Yes means the model keeps the original total payment budget after a debt is paid off; No lets the modeled monthly payment decline as debts drop out. It is not an automatic creditor transfer between accounts.
• Treating the avalanche order as account-specific advice. The app sorts by entered annual rates and starting balances; it does not evaluate minimum-payment rules, legal risk, collections, settlement offers, credit-reporting consequences, cash-flow hardship, taxes, or whether a different repayment method fits a personal situation.

Methodology and sources

This calculator is an original implementation based on the app's documented multi-debt avalanche simulation, fixed planning assumptions, deterministic fixtures, edge cases, rounding policy tests, and internal validation. It is not copied from a single source.

Outputs are checked with deterministic fixtures, edge cases, rounding policy tests, and internal validation artifacts. The result remains an educational estimate, not a creditor payoff quote, issuer payment-allocation rule, debt-management plan, settlement strategy, counseling recommendation, bankruptcy answer, tax answer, legal answer, credit-reporting forecast, regulated debt advice, or personalised advice.

Formula version 2026.05.22-generic-debt-avalanche. The version marks the calculation logic and validation fixture set used for this estimate.

• CFPB debt collection resources should be used before copy discusses collectors, debt validation, consumer rights, complaints, collection communications, lawsuits, garnishment, or collection-account context.
• CFPB credit-counseling, debt-settlement, debt-consolidation, and credit-repair guidance plus FTC debt guidance should be used before copy discusses debt-management plans, settlement risks, consolidation costs, credit repair, debt-relief providers, upfront fees, scams, or repayment proposals to collectors.
• CFPB credit-card interest guidance and Regulation Z section 1026.53 should be used before copy discusses real card APR buckets, excess-payment allocation, deferred-interest balances, promotional balances, issuer allocation rules, or card-specific payoff behavior.
• Lender and servicer agreements, credit-card agreements, tax authorities, bankruptcy materials, credit-reporting sources, legal sources, debt-counseling providers, and local regulators should be used before copy makes product-specific, fee, hardship-plan, default, lawsuit, garnishment, forgiven-debt tax, credit-reporting, legal, regulated-advice, or jurisdiction-specific claims.

Estimate only

The result is educational and is not financial, tax, legal, lending, investment, or regulated advice. Real provider terms, fees, rates, taxes, and personal circumstances can change the final answer.

Formula and help: read the full debt payoff calculator methodology notes.

Related reading

• Budgeting with monthly and yearly numbers
• How Calcs.finance validates calculator formulas
• Estimate limitations and not-advice disclaimer

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