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How to Calculate Loan

What is Loan?

A loan payment calculator determines your fixed monthly payment using the amortization formula. Each payment covers accrued interest first, with the remainder reducing the principal. Early payments are mostly interest; later payments are mostly principal.

Step-by-Step Guide

  1. 1Determine the principal P (amount borrowed)
  2. 2Convert annual rate to monthly: r = annual rate ÷ 12
  3. 3Set n = total number of monthly payments (years × 12)
  4. 4Apply: M = P × r(1+r)ⁿ / ((1+r)ⁿ − 1)
  5. 5Total interest paid = (M × n) − P

Worked Examples

Input
$10,000 at 6% for 3 years
Result
$304.22/month
Total paid: $10,951.92 — Interest: $951.92
Input
$250,000 mortgage at 7% for 30 years
Result
$1,663.26/month
Total interest: $348,773 — more than the loan!
Input
$20,000 car at 5% for 5 years
Result
$377.42/month
Total paid: $22,645.20

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