Debt Payoff Calculator
See how fast you can eliminate debt with extra payments. Months = -log(1 - (B * r / P)) / log(1 + r), where B = balance, r = monthly rate (APR / 12), P = monthly payment. Total Interest = (Months * P) - B. Calculation is done twice: once with P = Minimum Monthly Payment, and once with P = Minimum Monthly Payment + Extra Monthly Payment. Time Saved = Months(min) - Months(extra). Interest Saved = Total Interest(min) - Total Interest(extra). How it works If your debt APR exceeds what you'd earn investing, paying off debt first gives a guaranteed return. Validation: Only valid when P > B * r (payment exceeds monthly interest); If payment is less than monthly interest, debt grows instead of shrinking