Free Debt Payoff Calculator
Calculate how long it will take to pay off any debt and the total interest you will pay.
USD
%
USD
Months to Pay Off
48
Total Paid$19,200.00
Total Interest$4,200.00
Months to Pay Off vs Monthly Payment
Debt Payoff Formula
Months = -log(1 - r × D / P) / log(1 + r)
Where D = debt, P = monthly payment, r = monthly rate. Payment must exceed monthly interest (D × r) for the debt to decrease.
Example Calculation
$15,000 debt at 12% APR with $400 monthly payments.
- 01Monthly rate = 12% / 12 = 1%
- 02Months = -log(1 - 0.01 × 15000 / 400) / log(1.01)
- 03= -log(0.625) / 0.00995 = 47.2 → 48 months (4 years)
- 04Total paid = 48 × $400 = $19,200
- 05Total interest = $19,200 - $15,000 = $4,200
Frequently Asked Questions
Learn More
How to Calculate Mortgage Payments
Learn how to calculate mortgage payments step by step. Understand the mortgage payment formula, principal vs. interest breakdown, escrow, PMI, and how to use amortization schedules.