Skip to main content

How to Calculate Simple Loan

What is Simple Loan?

A simple loan calculator computes monthly payments and total interest for a standard installment loan (mortgage, auto loan, personal loan). It uses the standard amortization formula where equal monthly payments cover both principal and interest.

Step-by-Step Guide

  1. 1Monthly payment = P × r(1+r)^n / ((1+r)^n − 1)
  2. 2Each payment covers that month's interest first, then reduces principal
  3. 3Total cost = Monthly payment × number of payments
  4. 4Total interest = Total cost − Original principal

Worked Examples

Input
$15,000 personal loan, 9% APR, 48 months
Result
$373/month, $2,916 interest
Total cost: $17,916
Input
$250,000 mortgage, 6.5%, 30 years
Result
$1,580/month, $318,753 interest
Pay 2.3× the loan amount

Ready to calculate? Try the free Simple Loan Calculator

Try it yourself →

Settings

PrivacyTermsAbout© 2026 PrimeCalcPro