Personal Loan Payoff Calculator
Calculate your exact monthly payment on a personal loan, including processing fees and extra payments. Use it to compare loan offers and see your full amortization cost before you sign.
About this calculator
Monthly loan payments are determined by the standard amortization formula applied to the loan principal adjusted for any upfront processing fee. The total monthly payment is: Payment = [(loanAmount × (1 + processingFee/100)) × (r × (1+r)^n) / ((1+r)^n − 1)] + extraMonthlyPayment, where r = annualRate / 100 / 12 (monthly interest rate) and n = termLength (number of months). The processing fee is folded into the principal because it is typically financed rather than paid upfront. The extra monthly payment is added on top and reduces principal faster, shortening the effective loan term. Total interest paid equals (monthly payment × n) minus the adjusted principal. Understanding this formula helps you evaluate whether a low-rate loan with a high processing fee is truly cheaper than a higher-rate loan with no fee.
How to use
Assume a $10,000 loan at 12% annual interest, 36-month term, 2% processing fee, and $50 extra monthly payment. Adjusted principal = $10,000 × 1.02 = $10,200. Monthly rate r = 0.12/12 = 0.01. Base payment = $10,200 × (0.01 × 1.01^36) / (1.01^36 − 1). Calculate: 1.01^36 ≈ 1.4308; numerator = 0.01 × 1.4308 = 0.014308; denominator = 0.4308; base payment = $10,200 × 0.03321 ≈ $338.75. Total monthly payment = $338.75 + $50 = $388.75. Total paid over 36 months at base rate ≈ $12,195, so total interest ≈ $1,995 before the extra payment benefit.
Frequently asked questions
How does a processing fee affect the total cost of a personal loan?
A processing fee increases the effective principal you are financing, which raises both your monthly payment and total interest paid. For example, a 3% fee on a $15,000 loan adds $450 to your financed balance, and you pay interest on that $450 for the entire loan term. When comparing loan offers, always calculate the APR inclusive of fees rather than relying on the stated interest rate alone. A loan with a lower interest rate but a high processing fee can easily cost more in total than a slightly higher-rate loan with no fee.
What happens to my loan payoff date when I make extra monthly payments?
Extra monthly payments go directly toward reducing your principal balance, which lowers the amount of interest charged in every subsequent month. This creates a compounding benefit — each extra payment saves you more interest than its face value. Depending on your loan size and rate, even $25–$50 extra per month can cut months off your repayment schedule. This calculator shows your adjusted total payment including the extra amount, helping you quantify exactly how much time and interest you save.
Why does my personal loan payment stay the same each month even though my balance is decreasing?
Standard amortizing loans use a fixed monthly payment calculated at origination so the loan is fully paid off in exactly the agreed term. Each payment covers that month's interest first, and the remainder reduces principal. Early in the loan, most of your payment goes to interest; later, most goes to principal — but the total dollar amount stays constant. This structure makes budgeting predictable. If you want to pay off faster, adding extra payments above the fixed amount is the most straightforward approach.