Include credit cards, car loans, student loans, etc. (excluding rent/current mortgage).
The amount you have saved for the down payment.
Current market rates or your expected rate.
15 Years
30 Years
20 Years
25 Years
The duration of the mortgage.
Estimate based on home location.
Estimate based on home value and location.
Private Mortgage Insurance, often required for low down payments.
Understanding Your Mortgage Affordability
Determining "what can I afford mortgage loan" is a crucial first step before diving into the exciting world of homeownership. This involves more than just looking at your bank account; it requires a comprehensive understanding of your income, expenses, and the true cost of owning a home, which includes not only the principal and interest on your loan but also property taxes, homeowners insurance, and potentially Private Mortgage Insurance (PMI). Our What Can I Afford Mortgage Loan Calculator is designed to provide a realistic estimate of your home buying power, helping you make informed financial decisions and avoid overextending yourself. Understanding your affordability is key to a successful and stress-free home buying journey, making this What Can I Afford Mortgage Loan Calculator an indispensable tool.
Your Estimated Affordability
$0
Max Monthly P&I:$0Estimated Total Monthly Payment:$0Recommended Max Home Price:$0
Calculated based on DTI ratios, PITI components, and lender guidelines for What Can I Afford Mortgage Loan.
Breakdown of Estimated Monthly Housing Costs
Year
Starting Balance
Principal Paid
Interest Paid
Ending Balance
Estimated Amortization Schedule (First 5 Years)
var chartInstance = null; // Global variable to hold chart instance
function formatCurrency(amount) {
return "$" + parseFloat(amount).toFixed(2).replace(/\B(?=(\d{3})+(?!\d))/g, ",");
}
function formatNumber(number) {
return parseFloat(number).toFixed(2).replace(/\B(?=(\d{3})+(?!\d))/g, ",");
}
function showError(elementId, message) {
var errorElement = document.getElementById(elementId + 'Error');
if (errorElement) {
errorElement.textContent = message;
}
}
function clearErrors() {
var errorElements = document.querySelectorAll('.error-message');
for (var i = 0; i < errorElements.length; i++) {
errorElements[i].textContent = '';
}
}
function validateInputs() {
clearErrors();
var isValid = true;
var inputs = {
monthlyIncome: { min: 0, max: Infinity, msg: "Income must be a positive number." },
monthlyDebt: { min: 0, max: Infinity, msg: "Debt payments must be a non-negative number." },
downPayment: { min: 0, max: Infinity, msg: "Down payment must be a non-negative number." },
interestRate: { min: 0.1, max: 30, msg: "Interest rate must be between 0.1% and 30%." },
propertyTaxRate: { min: 0, max: 10, msg: "Property tax rate must be between 0% and 10%." },
homeInsuranceRate: { min: 0, max: 5, msg: "Home insurance rate must be between 0% and 5%." },
pmiRate: { min: 0, max: 5, msg: "PMI rate must be between 0% and 5%." }
};
for (var id in inputs) {
var element = document.getElementById(id);
var value = parseFloat(element.value);
if (isNaN(value) || value inputs[id].max) {
showError(id, inputs[id].msg);
isValid = false;
}
}
return isValid;
}
function calculateAffordability() {
if (!validateInputs()) {
return;
}
var monthlyIncome = parseFloat(document.getElementById('monthlyIncome').value);
var monthlyDebt = parseFloat(document.getElementById('monthlyDebt').value);
var downPayment = parseFloat(document.getElementById('downPayment').value);
var interestRate = parseFloat(document.getElementById('interestRate').value) / 100;
var loanTerm = parseInt(document.getElementById('loanTerm').value);
var propertyTaxRate = parseFloat(document.getElementById('propertyTaxRate').value) / 100;
var homeInsuranceRate = parseFloat(document.getElementById('homeInsuranceRate').value) / 100;
var pmiRate = parseFloat(document.getElementById('pmiRate').value) / 100;
// Lender DTI Guidelines (common conservative estimates)
var maxFrontEndDTIRatio = 0.28; // Max housing payment to gross income
var maxBackEndDTIRatio = 0.43; // Max total debt to gross income
// Calculate Maximum Allowable Monthly Housing Payment
var maxTotalDebtAllowed = monthlyIncome * maxBackEndDTIRatio;
var maxHousingPaymentAllowed = maxTotalDebtAllowed – monthlyDebt;
if (maxHousingPaymentAllowed <= 0) {
document.getElementById('maxMortgageAmount').innerText = "$0";
document.getElementById('maxMonthlyPI').innerText = "$0";
document.getElementById('estimatedTotalMonthlyPayment').innerText = "$0";
document.getElementById('recommendedMaxHomePrice').innerText = formatCurrency(downPayment);
updateChartAndTable(0, 0, 0, 0, 0, 0); // Clear chart and table
return;
}
// — Iterative Calculation for Max Loan Amount —
// This is a simplified iterative approach. A direct formula is complex due to dependencies.
var estimatedMaxLoan = maxHousingPaymentAllowed * 12 * loanTerm; // Initial guess
var bestLoanAmount = 0;
var tolerance = 1; // Allowable difference in monthly payment
var maxIterations = 100;
var iteration = 0;
while (iteration < maxIterations) {
var currentHomeValue = estimatedMaxLoan + downPayment;
if (currentHomeValue 0) {
pAndI = estimatedMaxLoan * (monthlyInterestRate * Math.pow(1 + monthlyInterestRate, numPayments)) / (Math.pow(1 + monthlyInterestRate, numPayments) – 1);
} else {
pAndI = estimatedMaxLoan / numPayments; // Handle 0% interest rate
}
var monthlyPropertyTax = (propertyTaxRate * currentHomeValue) / 12;
var monthlyHomeInsurance = (homeInsuranceRate * currentHomeValue) / 12;
var monthlyPMI = 0;
// Only include PMI if down payment is less than 20% of estimated home value
if (downPayment < currentHomeValue * 0.20) {
monthlyPMI = (pmiRate * estimatedMaxLoan) / 12;
}
var totalMonthlyHousingCost = pAndI + monthlyPropertyTax + monthlyHomeInsurance + monthlyPMI;
// Check if the calculated housing cost fits within the allowed budget
if (totalMonthlyHousingCost <= maxHousingPaymentAllowed) {
// If it fits, this loan amount is potentially affordable. Try a slightly higher amount.
bestLoanAmount = estimatedMaxLoan; // Store this valid amount
estimatedMaxLoan *= 1.005; // Increase loan amount slightly to find the true maximum
} else {
// If it exceeds the budget, reduce the loan amount.
estimatedMaxLoan *= 0.995; // Decrease loan amount slightly
}
// Break if the loan amount becomes negligible or negative
if (estimatedMaxLoan 0) {
finalPandI = estimatedMaxLoan * (finalMonthlyInterestRate * Math.pow(1 + finalMonthlyInterestRate, finalNumPayments)) / (Math.pow(1 + finalMonthlyInterestRate, finalNumPayments) – 1);
} else {
finalPandI = estimatedMaxLoan / finalNumPayments; // Handle 0% interest rate
}
var finalMonthlyPropertyTax = (propertyTaxRate * finalHomeValue) / 12;
var finalMonthlyHomeInsurance = (homeInsuranceRate * finalHomeValue) / 12;
var finalMonthlyPMI = 0;
if (downPayment < finalHomeValue * 0.20) {
finalMonthlyPMI = (pmiRate * estimatedMaxLoan) / 12;
}
var finalTotalMonthlyHousingCost = finalPandI + finalMonthlyPropertyTax + finalMonthlyHomeInsurance + finalMonthlyPMI;
// Ensure results are not negative or NaN
finalPandI = Math.max(0, finalPandI);
finalTotalMonthlyHousingCost = Math.max(0, finalTotalMonthlyHousingCost);
finalHomeValue = Math.max(downPayment, finalHomeValue); // Home value must be at least down payment
document.getElementById('maxMortgageAmount').innerText = formatCurrency(estimatedMaxLoan);
document.getElementById('maxMonthlyPI').innerText = formatCurrency(finalPandI);
document.getElementById('estimatedTotalMonthlyPayment').innerText = formatCurrency(finalTotalMonthlyHousingCost);
document.getElementById('recommendedMaxHomePrice').innerText = formatCurrency(finalHomeValue);
// Update Chart and Table
updateChartAndTable(finalHomeValue, finalPandI, finalMonthlyPropertyTax, finalMonthlyHomeInsurance, finalMonthlyPMI, finalTotalMonthlyHousingCost);
}
function updateChartAndTable(homeValue, monthlyPI, monthlyTax, monthlyInsurance, monthlyPMI, totalMonthlyCost) {
var ctx = document.getElementById('affordabilityChart').getContext('2d');
// Destroy previous chart instance if it exists
if (chartInstance) {
chartInstance.destroy();
}
// Prepare chart data
var labels = ['Principal & Interest', 'Property Tax', 'Home Insurance', 'PMI'];
var dataValues = [monthlyPI, monthlyTax, monthlyInsurance, monthlyPMI];
// Filter out zero values to keep the chart clean
var filteredLabels = [];
var filteredDataValues = [];
for (var i = 0; i 0) {
filteredLabels.push(labels[i]);
filteredDataValues.push(dataValues[i]);
}
}
// Add a "Total" if there are components
if (filteredDataValues.length > 0) {
filteredLabels.push('Total Housing Cost');
filteredDataValues.push(totalMonthlyCost);
} else { // If no components, just show the total which should be 0
filteredLabels.push('Total Housing Cost');
filteredDataValues.push(0);
}
chartInstance = new Chart(ctx, {
type: 'bar',
data: {
labels: filteredLabels,
datasets: [{
label: 'Estimated Monthly Cost',
data: filteredDataValues,
backgroundColor: [
'rgba(0, 74, 153, 0.6)', // P&I
'rgba(40, 167, 69, 0.6)', // Tax
'rgba(255, 193, 7, 0.6)', // Insurance
'rgba(220, 53, 69, 0.6)', // PMI
'rgba(0, 0, 0, 0.8)' // Total
],
borderColor: [
'rgba(0, 74, 153, 1)',
'rgba(40, 167, 69, 1)',
'rgba(255, 193, 7, 1)',
'rgba(220, 53, 69, 1)',
'rgba(0, 0, 0, 1)'
],
borderWidth: 1
}]
},
options: {
responsive: true,
maintainAspectRatio: false,
scales: {
y: {
beginAtZero: true,
title: {
display: true,
text: 'Amount ($)'
}
}
},
plugins: {
legend: {
display: false // Labels in dataset are sufficient for this case
},
tooltip: {
callbacks: {
label: function(context) {
var label = context.dataset.label || ";
if (label) {
label += ': ';
}
if (context.parsed.y !== null) {
label += formatCurrency(context.parsed.y);
}
return label;
}
}
}
}
}
});
// — Update Amortization Table —
var tableBody = document.querySelector("#amortizationTable tbody");
tableBody.innerHTML = "; // Clear existing rows
var principalLoan = parseFloat(document.getElementById('maxMortgageAmount').innerText.replace(/[\$,]/g, "));
var annualInterestRate = parseFloat(document.getElementById('interestRate').value) / 100;
var loanTermYears = parseInt(document.getElementById('loanTerm').value);
var monthlyInterestRateCalc = annualInterestRate / 12;
var numPaymentsCalc = loanTermYears * 12;
var currentBalance = principalLoan;
var totalPrincipalPaid = 0;
var totalInterestPaid = 0;
// Calculate for the first 5 years
var yearsToShow = Math.min(loanTermYears, 5);
for (var year = 1; year <= yearsToShow; year++) {
var startBalanceYear = currentBalance;
var yearPrincipalPaid = 0;
var yearInterestPaid = 0;
for (var month = 0; month < 12; month++) {
if (currentBalance 0) {
monthlyPaymentFormula = principalLoan * (monthlyInterestRateCalc * Math.pow(1 + monthlyInterestRateCalc, numPaymentsCalc)) / (Math.pow(1 + monthlyInterestRateCalc, numPaymentsCalc) – 1);
} else {
monthlyPaymentFormula = principalLoan / numPaymentsCalc;
}
principalPayment = monthlyPaymentFormula – interestPayment;
// Adjust principal payment for the final month to avoid overpayment
if (currentBalance – principalPayment < 0) {
principalPayment = currentBalance;
}
currentBalance -= principalPayment;
yearInterestPaid += interestPayment;
yearPrincipalPaid += principalPayment;
// Ensure balance doesn't go below zero due to floating point errors
if (currentBalance < 0) currentBalance = 0;
}
totalPrincipalPaid += yearPrincipalPaid;
totalInterestPaid += yearInterestPaid;
var row = tableBody.insertRow();
row.insertCell(0).innerText = year;
row.insertCell(1).innerText = formatCurrency(startBalanceYear);
row.insertCell(2).innerText = formatCurrency(yearPrincipalPaid);
row.insertCell(3).innerText = formatCurrency(yearInterestPaid);
row.insertCell(4).innerText = formatCurrency(currentBalance);
}
}
function resetCalculator() {
document.getElementById('monthlyIncome').value = '';
document.getElementById('monthlyDebt').value = '';
document.getElementById('downPayment').value = '';
document.getElementById('interestRate').value = '7';
document.getElementById('loanTerm').value = '30';
document.getElementById('propertyTaxRate').value = '1.2';
document.getElementById('homeInsuranceRate').value = '0.5';
document.getElementById('pmiRate').value = '0.5';
document.getElementById('maxMortgageAmount').innerText = "$0";
document.getElementById('maxMonthlyPI').innerText = "$0";
document.getElementById('estimatedTotalMonthlyPayment').innerText = "$0";
document.getElementById('recommendedMaxHomePrice').innerText = "$0";
clearErrors();
// Clear chart and table
if (chartInstance) {
chartInstance.destroy();
chartInstance = null;
}
var tableBody = document.querySelector("#amortizationTable tbody");
tableBody.innerHTML = '';
}
function copyResults() {
var maxMortgage = document.getElementById('maxMortgageAmount').innerText;
var maxMonthlyPI = document.getElementById('maxMonthlyPI').innerText;
var estimatedTotalMonthly = document.getElementById('estimatedTotalMonthlyPayment').innerText;
var recommendedMaxHome = document.getElementById('recommendedMaxHomePrice').innerText;
var summary = "Your Estimated Home Affordability:\n";
summary += "———————————-\n";
summary += "Max Loan Amount: " + maxMortgage + "\n";
summary += "Max Monthly P&I: " + maxMonthlyPI + "\n";
summary += "Estimated Total Monthly Payment (PITI+PMI): " + estimatedTotalMonthly + "\n";
summary += "Recommended Max Home Price: " + recommendedMaxHome + "\n";
// Use a temporary textarea to copy to clipboard
var textArea = document.createElement("textarea");
textArea.value = summary;
textArea.style.position = "fixed"; // Avoid scrolling to bottom of page
textArea.style.left = "-infinity";
textArea.style.top = "-infinity";
document.body.appendChild(textArea);
textArea.focus();
textArea.select();
try {
var successful = document.execCommand('copy');
var msg = successful ? 'Copied!' : 'Copy failed!';
// Optional: Show a temporary message to the user
var copyButton = document.querySelector('.results-output .copy-button');
var originalText = copyButton.innerText;
copyButton.innerText = msg;
setTimeout(function() {
copyButton.innerText = originalText;
}, 1500);
} catch (err) {
console.error('Fallback: Oops, unable to copy', err);
var copyButton = document.querySelector('.results-output .copy-button');
copyButton.innerText = 'Copy failed!';
setTimeout(function() {
copyButton.innerText = 'Copy Results';
}, 1500);
}
document.body.removeChild(textArea);
}
// Add Chart.js to the page dynamically (or include via CDN in a real application)
// For this single-file HTML, we need to include it.
// In a real WordPress theme, you'd enqueue this script properly.
var chartJsScript = document.createElement('script');
chartJsScript.src = 'https://cdn.jsdelivr.net/npm/chart.js@3.9.1/dist/chart.min.js';
chartJsScript.onload = function() {
console.log("Chart.js loaded.");
// Optionally call calculateAffordability() here if you want the chart/table
// to render with default values on page load, but it's better to trigger manually.
};
chartJsScript.onerror = function() {
console.error("Failed to load Chart.js. Chart and table functionality will be disabled.");
// Disable chart/table related UI or show an error message
document.getElementById('affordabilityChart').style.display = 'none';
document.getElementById('amortizationTable').style.display = 'none';
var chartCaption = document.querySelector('.chart-caption');
if(chartCaption) chartCaption.innerText = "Chart unavailable (Chart.js failed to load)";
var tableCaption = document.querySelector('.table-caption');
if(tableCaption) tableCaption.innerText = "Table unavailable (Chart.js failed to load)";
};
document.head.appendChild(chartJsScript);
// Initial calculation on load with default values if desired
// document.addEventListener('DOMContentLoaded', function() {
// calculateAffordability();
// });