Mortgage Closing Cost Calculator

Mortgage Repayment Calculator

Estimate your monthly home loan payments and total interest costs.

30 Years 20 Years 15 Years 10 Years

Summary

Monthly Payment
$2,022.62
Total Principal
$320,000.00
Total Interest
$408,143.20
Total Cost of Loan
$728,143.20

How to Use the Mortgage Repayment Calculator

Choosing a home is one of the most significant financial decisions you will ever make. Our mortgage repayment calculator helps you understand the long-term financial commitment by breaking down your monthly principal and interest payments. By adjusting the home price, down payment, and interest rates, you can see how different scenarios impact your monthly budget.

The Mortgage Math Explained

Mortgage payments are calculated using an amortization formula. Unlike simple interest, a mortgage is structured so that in the early years, a larger portion of your payment goes toward interest, while in later years, more goes toward the principal. The formula used is:

M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1 ]
  • M: Total monthly payment
  • P: Principal loan amount (Home price minus down payment)
  • i: Monthly interest rate (Annual rate divided by 12)
  • n: Number of months (Years multiplied by 12)

Realistic Example Case Study

Imagine you are purchasing a home for $500,000 with a 20% down payment ($100,000). This leaves you with a loan amount of $400,000. At a fixed interest rate of 7.0% over a 30-year term:

  • Monthly Payment: $2,661.21
  • Total Interest Paid: $558,035.60
  • Total Cost of Loan: $958,035.60

By increasing your down payment to 25%, you would reduce your monthly payment and save tens of thousands in interest over the life of the loan.

Key Factors Influencing Your Payment

1. Down Payment: A higher down payment reduces the principal. If you put down less than 20%, you may also need to account for Private Mortgage Insurance (PMI), which is not included in this basic calculator but usually adds 0.5% to 1.5% to your annual cost.

2. Interest Rates: Even a 0.5% difference in your interest rate can result in huge savings. It is vital to shop around for the best rates from different lenders.

3. Loan Term: A 15-year mortgage usually has a lower interest rate and results in much less total interest paid, but the monthly payments are significantly higher than a 30-year mortgage.

function calculateMortgage() { var homePrice = parseFloat(document.getElementById("homePrice").value); var downPayment = parseFloat(document.getElementById("downPayment").value); var termYears = parseInt(document.getElementById("loanTerm").value); var annualRate = parseFloat(document.getElementById("interestRate").value); if (isNaN(homePrice) || isNaN(downPayment) || isNaN(annualRate) || homePrice <= 0) { alert("Please enter valid positive numbers."); return; } var principal = homePrice – downPayment; if (principal <= 0) { document.getElementById("monthlyPaymentDisplay").innerText = "$0.00"; document.getElementById("totalPrincipalDisplay").innerText = "$0.00"; document.getElementById("totalInterestDisplay").innerText = "$0.00"; document.getElementById("totalCostDisplay").innerText = "$0.00"; return; } var monthlyRate = (annualRate / 100) / 12; var numberOfPayments = termYears * 12; var monthlyPayment = 0; if (monthlyRate === 0) { monthlyPayment = principal / numberOfPayments; } else { monthlyPayment = principal * (monthlyRate * Math.pow(1 + monthlyRate, numberOfPayments)) / (Math.pow(1 + monthlyRate, numberOfPayments) – 1); } var totalCost = monthlyPayment * numberOfPayments; var totalInterest = totalCost – principal; document.getElementById("monthlyPaymentDisplay").innerText = formatCurrency(monthlyPayment); document.getElementById("totalPrincipalDisplay").innerText = formatCurrency(principal); document.getElementById("totalInterestDisplay").innerText = formatCurrency(totalInterest); document.getElementById("totalCostDisplay").innerText = formatCurrency(totalCost); } function formatCurrency(num) { return "$" + num.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2}); } // Initialize on load window.onload = function() { calculateMortgage(); };
@media (max-width: 768px) { #mortgage-calculator-container div[style*="grid-template-columns: 1fr 1fr"] { grid-template-columns: 1fr !important; } }

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