Loan Payment Calculator
Calculate your monthly loan payment, total interest, and full repayment cost.
Updated April 2026 · CalcFlow Editorial
What is a Loan Payment? A loan payment calculator computes the fixed monthly payment for an installment loan using the amortization formula M = P x [r(1+r)^n] / [(1+r)^n - 1], where P is the principal, r is the monthly interest rate, and n is the total number of payments.
Rule of Thumb
A rough estimate: for every $10,000 borrowed at 7% over 5 years, expect a monthly payment of about $198. Each extra percentage point in rate adds roughly $5/month per $10,000 borrowed. Doubling the loan term cuts the monthly payment nearly in half but more than doubles total interest paid.
Example Calculation
$15,000 personal loan at 9% APR over 4 years: monthly rate = 0.75%, n = 48 payments. Monthly payment = $373. Total paid = $17,904. Total interest = $2,904 (19.4% of loan).
Key Facts
- •Average personal loan interest rate in Q1 2025 was 12.37% APR for a 24-month loan (Federal Reserve G.19 data).
- •Paying one extra monthly payment per year on a 5-year loan at 8% cuts total interest by approximately 14%.
- •The first payment on a standard amortizing loan goes mostly to interest; over time, the split shifts toward principal.
- •Origination fees (typically 1-8% of loan amount) are not captured in the monthly payment formula but add to total borrowing cost.
How to Use
- Enter the total loan amount.
- Enter the annual interest rate.
- Set the loan term in years.
- Click Calculate to see your monthly payment and total interest.
Formula
M = P x [r(1+r)^n] / [(1+r)^n - 1] where r = monthly rate, n = number of payments