Student Loan Repayment Calculator Overlay

WHAT IT DOES

This userscript helps students and graduates understand their loan repayment options by providing an interactive calculator. It scans student loan pages, financial aid portals, or loan servicer websites for loan details—total loan amount, interest rate, loan term, monthly payment, and repayment plan. It displays an interactive calculator panel to simulate repayment scenarios, extract loan figures from text, calculate monthly payments, total interest, and total cost over different repayment plans (Standard 10-year, Extended 25-year, Extended Graduate 25-year, Income-Driven 20-25 year). The script compares plans side-by-side, shows amortization schedules, highlights the cheapest plan, and exports the calculation as CSV or HTML. It suggests the fastest payoff strategy and shows the impact of extra payments.

WHERE IT RUNS

The script works on student loan pages, financial aid portals, loan servicer websites, and any page with loan details. 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 loan 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 loan amount, interest rate, and select a repayment term. Add extra payments to see how much interest you can save. Click "Calculate" to see monthly payment, total interest, total cost, and payoff time. Click "View Amortization Schedule" to see a year-by-year breakdown of remaining balance, total paid, and total interest. Use "Extract from page" to auto-fill loan details from the current page. Use the export dropdown to choose your format—CSV or HTML (report). Click "Export" to download.

THE TECHNICAL MECHANISM

This script uses standard loan amortization formulas to calculate repayment scenarios. The monthly payment is calculated using the formula: P = principal × (r(1+r)^n) / ((1+r)^n - 1), where r is the monthly interest rate and n is the number of months. The repayment simulation iterates month by month, applying the monthly payment, calculating interest on the remaining balance, and tracking total interest and total paid. Extra payments reduce the principal faster and shorten the term. The amortization schedule captures key metrics at annual intervals. The HTML export generates a styled report with all metrics. 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 loan 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 amortization schedule opens in a new window—please allow popups. 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.