Amortization Calculator

Amortization Calculator

Build a complete loan amortization schedule with optional extra payments.

UNDERSTAND THE ANSWER

How is this calculated?

Each month’s interest equals the opening balance times the monthly rate. The rest of the scheduled payment plus any extra amount reduces principal.

Fixed-rate amortizationPayment = P × [r(1 + r)ⁿ] ÷ [(1 + r)ⁿ − 1]

A practical example

A $300,000 loan at 6.5% for 30 years requires about $1,896 monthly before taxes, insurance and fees.

Assumptions, interpretation and common mistakes

Calculation assumptions

  • The interest rate and required payment remain fixed.
  • Payments occur monthly beginning on the selected date.
  • Extra payments are applied to principal each month without fees or penalties.

How to interpret the result

  • The required payment excludes taxes, insurance and loan fees.
  • Early payments contain more interest because the balance is larger.
  • The annual and monthly tables show how principal reduction accelerates over time.

Common mistakes to avoid

  • Reading the payment as an all-in mortgage housing cost.
  • Assuming a lender applies extra funds to principal automatically.
  • Comparing loans without including points, closing costs and other fees.