Mortgage Calculator

Plan your home financing and see the impact of extra payments

Mortgage Details

About Mortgages

A mortgage is a loan used to purchase real estate where the property serves as collateral. The borrower makes regular payments that cover both principal (the original loan amount) and interest (the cost of borrowing). Mortgages are typically long-term loans (15-30 years) with fixed or variable interest rates. Understanding your mortgage amortization schedule is crucial for financial planning as it shows how payments are split between principal and interest over time. Early payments primarily cover interest while later payments reduce principal faster. Extra payments can significantly reduce total interest paid and shorten loan term.

How It's Calculated

Monthly Payment Formula:

M = P × [r(1+r)^n] / [(1+r)^n - 1]

Where P = loan amount, r = monthly rate, n = total payments

Amortization:

Interest = Balance × Monthly Rate
Principal = Payment - Interest
New Balance = Old Balance - Principal

Each payment reduces balance and interest portion decreases over time

Extra Payment Impact:

Savings = Extra × [(1+r)^(n-k) - 1] / r

Where k = remaining payments, r = monthly rate

Key Insights

  • Early extra payments save significantly more interest due to compounding effect
  • Most of early payments go toward interest, not principal reduction
  • Lower interest rates dramatically reduce total cost of borrowing
  • Shorter loan terms save interest but increase monthly payments
  • $100 extra monthly payment on 30-year mortgage can save over $100,000 in interest