💰 Financial
Repayment Calculator
Estimate how long it will take to repay a debt based on a fixed monthly payment and an annual interest rate.
⏳
Formula
n = -log(1 - (P × r) / M) / log(1 + r)n- Total number of monthly payments
P- Principal balance
r- Monthly interest rate
M- Fixed monthly payment amount
Example
Repaying a $10,000 Debt
Figuring out the timeline for a $10,000 balance at 8% with a $300 monthly payment.
- Identify parameters: Balance = $10,000, Rate = 8%, Payment = $300.
- Convert rate to monthly: 0.08 / 12 = 0.00667.
- Apply formula: n = -log(1 - (10000 × 0.00667) / 300) / log(1 + 0.00667).
- Result: It will take 38.2 months (or 39 payments) to clear the debt.
Frequently Asked Questions
If your monthly payment is less than the monthly interest charge, your balance will grow instead of shrink. The calculator will indicate that the debt can never be repaid with that payment.