Please enter valid numbers in all fields.
';
if(roiChart) roiChart.destroy();
return;
}
const grossPotentialRent = monthlyRent * numUnits * 12;
const vacancyLoss = grossPotentialRent * (configData.vacancyRate / 100);
const effectiveGrossIncome = grossPotentialRent - vacancyLoss;
const operatingExpenses = effectiveGrossIncome * (configData.operatingExpensesRate / 100);
const netOperatingIncome = effectiveGrossIncome - operatingExpenses;
const totalCashFlow = netOperatingIncome * holdingPeriod;
const futureSalePrice = purchasePrice * Math.pow(1 + (configData.appreciationRate / 100), holdingPeriod);
const sellingCosts = futureSalePrice * (configData.sellingCostsRate / 100);
const netSaleProceeds = futureSalePrice - sellingCosts;
const totalProfit = (netSaleProceeds - purchasePrice) + totalCashFlow;
const totalROI = (totalProfit / purchasePrice) * 100;
const annualizedROI = Math.pow((totalProfit + purchasePrice) / purchasePrice, 1 / holdingPeriod) - 1;
renderResults(netOperatingIncome, totalROI, annualizedROI * 100);
updateChart(purchasePrice, totalProfit, totalCashFlow);
}
function renderResults(noi, totalRoi, annualizedRoi) {
resultsContent.innerHTML = `
Annual Net Operating Income (NOI)
$${noi.toLocaleString('en-US', {maximumFractionDigits: 0})}
Total Return on Investment (ROI)
${totalRoi.toFixed(1)}%
Over the full holding period
Annualized ROI
${annualizedRoi.toFixed(2)}%
Average annual return
`;
}
function updateChart(initialInvestment, totalProfit, cashFlow) {
const ctx = document.getElementById('roiChart').getContext('2d');
const appreciation = totalProfit - cashFlow;
if (roiChart) {
roiChart.destroy();
}
roiChart = new Chart(ctx, {
type: 'bar',
data: {
labels: ['Return Components'],
datasets: [
{ label: 'Initial Investment', data: [initialInvestment], backgroundColor: '#BDBDBD' },
{ label: 'Profit from Cash Flow', data: [cashFlow], backgroundColor: '#4CAF50' },
{ label: 'Profit from Appreciation', data: [appreciation], backgroundColor: '#81C784' }
]
},
options: {
indexAxis: 'y',
scales: { x: { stacked: true }, y: { stacked: true } },
plugins: {
title: { display: true, text: 'Investment vs. Return Breakdown' },
tooltip: {
callbacks: {
label: function(context) {
let label = context.dataset.label || '';
if (label) { label += ': '; }
if (context.parsed.x !== null) {
label += new Intl.NumberFormat('en-US', { style: 'currency', currency: 'USD' }).format(context.parsed.x);
}
return label;
}
}
}
}
}
});
}
function renderConfig() {
configTbody.innerHTML = `
| Vacancy Rate | |
| Operating Expenses Rate (% of EGI) | |
| Annual Property Appreciation Rate | |
| Selling Costs Rate | |
`;
}
window.updateConfig = function(element) {
const { prop } = element.dataset;
const value = parseFloat(element.value);
if (isNaN(value)) return;
configData[prop] = value;
calculateROI();
}
// --- TAB & NAVIGATION ---
window.openTab = function(evt, tabName) {
const tabContents = document.getElementsByClassName("tab-content");
Array.from(tabContents).forEach(tab => tab.style.display = "none");
const tabButtons = document.getElementsByClassName("tab-btn");
Array.from(tabButtons).forEach(btn => btn.classList.remove("active"));
document.getElementById(tabName).style.display = "block";
if (evt) {
evt.currentTarget.classList.add("active");
} else {
const btnToActivate = Array.from(tabButtons).find(btn => btn.getAttribute('onclick').includes(`'${tabName}'`));
if (btnToActivate) btnToActivate.classList.add("active");
}
updateNavButtons();
}
window.navigateTabs = function(direction) {
const tabs = Array.from(document.querySelectorAll('.tab-btn'));
const activeTabIndex = tabs.findIndex(tab => tab.classList.contains('active'));
let newIndex = (direction === 'next')
? (activeTabIndex + 1) % tabs.length
: (activeTabIndex - 1 + tabs.length) % tabs.length;
tabs[newIndex].click();
}
function updateNavButtons() {
const tabs = Array.from(document.querySelectorAll('.tab-btn'));
const activeTabIndex = tabs.findIndex(tab => tab.classList.contains('active'));
document.getElementById('prev-btn').style.visibility = activeTabIndex === 0 ? 'hidden' : 'visible';
document.getElementById('next-btn').style.visibility = activeTabIndex === tabs.length - 1 ? 'hidden' : 'visible';
}
// --- PDF DOWNLOAD ---
if(downloadPdfBtn) {
downloadPdfBtn.addEventListener('click', function() {
const { jsPDF } = window.jspdf;
const contentToDownload = document.getElementById('results-to-download');
if (!contentToDownload || !document.querySelector('.value')) {
console.warn("Please calculate an ROI before downloading.");
return;
}
const originalButtonText = downloadPdfBtn.innerHTML;
downloadPdfBtn.innerHTML = 'Generating...';
downloadPdfBtn.disabled = true;
html2canvas(contentToDownload, { scale: 2, useCORS: true }).then(canvas => {
const imgData = canvas.toDataURL('image/png');
const pdf = new jsPDF({ orientation: 'p', unit: 'mm', format: 'a4' });
const pdfWidth = pdf.internal.pageSize.getWidth();
const imgProps = pdf.getImageProperties(imgData);
const imgHeight = (imgProps.height * pdfWidth) / imgProps.width;
pdf.addImage(imgData, 'PNG', 10, 10, pdfWidth - 20, imgHeight > 0 ? imgHeight - 20 : 0);
pdf.save('Retirement-Home-ROI.pdf');
}).catch(err => {
console.error("Error generating PDF:", err);
}).finally(() => {
downloadPdfBtn.innerHTML = originalButtonText;
downloadPdfBtn.disabled = false;
});
});
}
// --- INITIALIZATION ---
function initializeTool() {
calculateROI();
renderConfig();
updateNavButtons();
}
initializeTool();
});
