Retirement Savings Contribution Calculator Overlay

WHAT IT DOES

This userscript helps you plan for retirement by projecting savings growth based on your current contributions and expected returns. It scans retirement planning pages, 401(k) portals, or financial websites for current retirement savings data—current balance, monthly contributions, employer match, expected return rate, and retirement age. It displays an interactive calculator panel to project future retirement savings, extract figures from text, calculate projected balance at retirement, show the impact of contribution increases, and display a growth chart over time. The script compares different contribution scenarios, shows the effect of employer matching, and exports the projection as CSV or HTML. It suggests contribution adjustments to meet retirement goals and shows the "magic number" needed for retirement.

WHERE IT RUNS

The script works on retirement planning pages, 401(k) portals, financial websites, and any page with retirement data. It runs entirely within your browser, reading only the visible content of the current page. It does not track your browsing history, access other tabs, or send any data externally. All retirement data is processed and stored locally.

HOW TO USE

After installation, open the panel by clicking the tool's icon in the BotGentz sidebar. Enter your current age, retirement age, current balance, monthly contribution, employer match (annual), and expected annual return. Click "Project Retirement" to calculate your projected balance at retirement. The results show projected balance, total contributions, employer match total, and total investment gain. A mini growth chart shows the balance trajectory over time. Use "Extract from page" to auto-fill retirement data from the current page. Use the export dropdown to choose your format—CSV or HTML (report). Click "Export" to download the year-by-year projection.

THE TECHNICAL MECHANISM

This script uses compound interest projections to model retirement savings growth. The projection runs month-by-month over the number of years until retirement. Each month: monthly contribution is added, employer match is added (annual match divided by 12), then the balance is multiplied by (1 + monthly return rate). The monthly return rate is calculated from the annual expected return divided by 12. The projection tracks balance, total contributions, and total employer match for each year. The growth chart is rendered as an SVG polyline showing the balance trend over time. The HTML export generates a styled report with summary metrics and a year-by-year table. All data is persisted using GM_setValue.

THE PANEL

The panel is draggable anywhere on the screen and remembers its position between sessions. It can be collapsed to a small floating bubble to minimize distraction, and expanded again with a single click. The panel's width can be adjusted, and pressing the Escape key closes it instantly. All settings and retirement data are persisted locally using GM_setValue, so your calculations remain intact across page reloads and browser restarts.

PLEASE NOTE

This userscript requires the free BotGentz extension to function. The script extracts figures from page text—it may not capture all numbers correctly. Review and adjust extracted data as needed. The projections are estimates based on assumed returns and do not guarantee actual results. The script does not access external APIs or store any data outside your browser. No data from your browsing is stored or transmitted anywhere—all processing occurs entirely in your browser.