Verified Mathematical Model & Formulation
Monthly Rate (r) = APR % / 1200 Months (n) = -log(1 - (Balance × r) / Payment) / log(1 + r) Total Payments = Monthly Payment × n Total Interest = Total Payments - Current Balance
Determines the number of repayment billing cycles necessary to liquidate revolving debt, factoring continuous monthly finance charges computed on daily/monthly balances.
Configurable Parameters & Standard Units
- Credit Card Balance ($): (Default: 6000 usd)
- Credit Card APR (%): (Default: 21.5 percent)
- Planned Monthly Payment ($): (Default: 250 usd)
Standard Worked Example & Practical Verification
Scenario: A cardholder owes $7,500 at 22.9% APR and commits to paying $300 fixed every month.
Practical Takeaway: Paying a fixed $300 rather than minimum payments saves thousands in predatory credit card interest charges.
Frequently Asked Questions
Why does paying only the minimum take decades to pay off?
Minimum payments are typically set at just 1% to 2% of principal plus accrued monthly interest. As the balance declines, the payment shrinks, dragging repayment across 15 to 30 years.
What is the debt avalanche vs debt snowball method?
The avalanche method prioritizes paying debts with the highest APR first to minimize interest cost, while the snowball method pays off the smallest balances first to build psychological momentum.