Roofstock Web Cash Flow Calculator Overlay

WHAT IT DOES

Roofstock Web Cash Flow Calculator Overlay automatically scans Roofstock rental property listing pages and extracts key property financial data including purchase price, gross monthly rent, property taxes, insurance premiums, HOA fees, vacancy estimates, management fees, and maintenance reserves. The tool calculates essential real estate investment metrics including net operating income (NOI), cash-on-cash return, cap rate, monthly cash flow, and annual cash flow. A floating overlay panel displays a detailed cash flow breakdown with color-coded indicators—green for positive returns and red for negative. Users can toggle between conservative, moderate, and optimistic scenarios to see how different expense assumptions impact investment returns. The scenario feature adjusts vacancy rates, management fees, maintenance reserves, and CapEx reserves accordingly. Your preferred scenario setting is saved across sessions for quick comparison.

WHERE IT RUNS

This extension operates exclusively on roofstock.com domain pages that contain property listing content—specifically pages with "/property", "/listings", or "/invest" in the URL path, or pages that display rental property financial details and investment data. It works alongside the free BotGentz companion extension, which provides the necessary DOM access and page interaction capabilities. The cash flow calculator runs entirely within your local browser instance and does not communicate with any external servers or APIs. All property data extraction, cash flow calculations, and scenario preferences are processed and stored on your machine, ensuring your investment analysis and financial data remain private. It supports all modern Chromium-based browsers (Chrome, Edge, Brave, Opera) and Firefox when paired with the BotGentz bridge.

HOW TO USE

After installing both BotGentz and this cash flow calculator, navigate to any Roofstock property listing page. Within 1-2 seconds, a panel appears in the bottom-right corner displaying the property address and key details including price, monthly rent, bedrooms, bathrooms, and square footage. The "Scenario" section lets you toggle between Conservative, Moderate, and Optimistic scenarios—each adjusts underlying expense assumptions to reflect different investment outlooks. The "Cash Flow" section displays monthly cash flow, annual cash flow (NOI), cash-on-cash return, and cap rate with color-coded performance indicators. The "Expenses" section shows a detailed breakdown of all expenses including vacancy, property taxes, insurance, HOA, management, maintenance, and CapEx reserves. Your selected scenario is saved automatically for future visits.

CASH FLOW CALCULATION AND SCENARIO ANALYSIS

The cash flow calculator uses a comprehensive financial model to evaluate rental property investments. The core calculation starts with gross annual rent (monthly rent × 12), then subtracts vacancy loss based on the vacancy rate assumption to determine effective gross income. Total expenses include property taxes, insurance, HOA fees, property management (percentage of gross rent), maintenance reserve (percentage of gross rent), and CapEx reserve (percentage of gross rent). Net operating income (NOI) is calculated as effective gross income minus total expenses. Monthly cash flow is NOI divided by 12. Cash-on-cash return is calculated as NOI divided by the purchase price, expressed as a percentage. Cap rate is calculated identically—NOI divided by purchase price. The scenario system adjusts key assumptions: Conservative uses 12% vacancy, 10% management, 8% maintenance, and 5% CapEx; Moderate uses 8% vacancy, 8% management, 5% maintenance, and 3% CapEx; Optimistic uses 5% vacancy, 6% management, 3% maintenance, and 2% CapEx. These adjustments provide a realistic range of potential investment outcomes.

THE PANEL

The cash flow calculator panel is a compact, functional overlay that integrates into the Roofstock property page. It can be dragged by clicking and holding the title bar, positioning the panel anywhere on the screen for optimal visibility while you analyze investment properties. The panel includes a built-in snap feature that automatically aligns to the nearest screen edge when released within 48 pixels, keeping your workspace organized. Click the collapse arrow in the top-right corner to minimize the panel to a small icon bubble showing a gear emoji, preserving screen space while keeping the tool accessible. The panel is not resizable in this version, maintaining a consistent compact size that works on all screen resolutions. Press the Escape key to instantly hide the panel; press Escape again to restore it. All position, collapse state, and scenario preferences are saved locally using GM_setValue and persist across browsing sessions.

PLEASE NOTE

This extension requires the free BotGentz extension to function—the cash flow calculator does not work standalone. Roofstock occasionally updates its page layouts and property presentation formats, which may temporarily affect financial data extraction accuracy. The tool extracts property data from the visible page content; if financial data is loaded dynamically after page load, you may need to wait a moment or refresh the page for the panel to populate. Cash flow calculations are estimates based on extracted data and scenario assumptions—always verify financial figures on the official Roofstock platform. The calculator does not account for financing costs, mortgage payments, or tax implications. The tool does not store or transmit any data; all property data extraction, cash flow calculations, and scenario preferences are processed and saved entirely within your browser. This tool is designed for personal investment analysis and is not affiliated with or endorsed by Roofstock or its parent company. Real estate investment involves risk; always consult with qualified professionals before making investment decisions.