Canada Home Loan Interest Rate Calculator

Mortgage Affordability Calculator

Understanding Mortgage Affordability

Buying a home is one of the most significant financial decisions you'll make. Determining how much mortgage you can realistically afford is a crucial first step. This calculator helps you estimate your maximum mortgage amount based on your income, existing debts, down payment, and prevailing interest rates.

Key Factors Affecting Affordability:

  • Annual Income: Lenders typically use your gross annual income to assess your ability to repay a loan. A higher income generally means you can afford a larger mortgage.
  • Monthly Debt Payments: Existing debts, such as car loans, student loans, and credit card payments, reduce the amount of income available for a mortgage. Lenders often look at your Debt-to-Income (DTI) ratio. A common guideline is that your total monthly debt payments (including the estimated mortgage payment) should not exceed 43% of your gross monthly income.
  • Down Payment: The larger your down payment, the less you need to borrow, which lowers your monthly payments and potentially the total interest paid over the life of the loan. A larger down payment can also help you avoid private mortgage insurance (PMI).
  • Interest Rate: This is the cost of borrowing money. Even small changes in the interest rate can significantly impact your monthly payment and the total interest paid over time.
  • Loan Term: The length of the loan (e.g., 15, 20, or 30 years). A shorter loan term means higher monthly payments but less total interest paid. A longer term results in lower monthly payments but more total interest paid.

How the Calculator Works:

This calculator uses a common lender guideline to estimate affordability. It considers your gross monthly income and subtracts your existing monthly debt payments. This remaining amount is then assessed against potential mortgage payments based on the interest rate and loan term you provide. The result gives you an estimated maximum loan amount you might qualify for, assuming other factors like credit score are favorable.

Disclaimer: This calculator provides an estimate only and should not be considered financial advice. Lender requirements and actual loan approval depend on many factors, including your credit score, employment history, loan-to-value ratio, and specific lender policies.

Example Calculation:

Let's say you have an Annual Income of $85,000, Total Monthly Debt Payments (excluding mortgage) of $400, a Down Payment of $30,000, an estimated Interest Rate of 6.0%, and you're considering a Loan Term of 30 years.

Your gross monthly income is $85,000 / 12 = $7,083.33.

A common DTI limit is 43%. So, your maximum total monthly debt payment could be around $7,083.33 * 0.43 = $3,045.83.

Subtracting your existing monthly debt of $400 leaves $2,645.83 for your maximum potential mortgage payment (principal and interest).

Using a mortgage payment formula with these figures, the calculator would estimate the maximum loan amount you could afford.

function calculateMortgageAffordability() { var annualIncome = parseFloat(document.getElementById("annualIncome").value); var monthlyDebt = parseFloat(document.getElementById("monthlyDebt").value); var downPayment = parseFloat(document.getElementById("downPayment").value); var interestRate = parseFloat(document.getElementById("interestRate").value); var loanTerm = parseFloat(document.getElementById("loanTerm").value); var resultDiv = document.getElementById("result"); if (isNaN(annualIncome) || isNaN(monthlyDebt) || isNaN(downPayment) || isNaN(interestRate) || isNaN(loanTerm)) { resultDiv.innerHTML = "Please enter valid numbers for all fields."; return; } if (annualIncome <= 0 || monthlyDebt < 0 || downPayment < 0 || interestRate <= 0 || loanTerm <= 0) { resultDiv.innerHTML = "Please enter positive values for income, interest rate, and loan term, and non-negative values for debt and down payment."; return; } var grossMonthlyIncome = annualIncome / 12; var maxTotalDebtPayment = grossMonthlyIncome * 0.43; // Using 43% DTI as a common guideline var maxMortgagePayment = maxTotalDebtPayment – monthlyDebt; if (maxMortgagePayment 0) { maxLoanAmount = maxMortgagePayment * (Math.pow(1 + monthlyInterestRate, numberOfPayments) – 1) / (monthlyInterestRate * Math.pow(1 + monthlyInterestRate, numberOfPayments)); } else { // Handle case of 0% interest rate (though highly unlikely for mortgages) maxLoanAmount = maxMortgagePayment * numberOfPayments; } var estimatedMaxHomePrice = maxLoanAmount + downPayment; resultDiv.innerHTML = "

Estimated Affordability

"; resultDiv.innerHTML += "Estimated Maximum Mortgage Loan Amount: $" + maxLoanAmount.toFixed(2) + ""; resultDiv.innerHTML += "Estimated Maximum Home Purchase Price (with down payment): $" + estimatedMaxHomePrice.toFixed(2) + ""; resultDiv.innerHTML += "This estimate assumes a 43% Debt-to-Income (DTI) ratio and does not include property taxes, homeowner's insurance, or PMI, which would increase your total monthly housing cost."; }

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