Side Hustle Income Tax Set-Aside Calculator

WHAT IT DOES

This userscript helps gig workers and freelancers estimate taxes and set aside the right amount from each payment. It scans any webpage for text-based income figures, payment amounts, or earnings from side hustles—freelance platforms, gig economy apps, invoicing pages—or allows manual entry, to calculate the recommended amount to set aside for estimated taxes. It extracts earnings from the page, applies tax rate estimates based on income level and filing status, calculates the total tax set-aside, and shows the remaining net income. The script tracks multiple income sources, suggests quarterly estimated tax payments, and exports the tax set-aside calculation as CSV or HTML. It accounts for deductions and self-employment tax (15.3%).

WHERE IT RUNS

The script works on any webpage with income figures—freelance platforms, gig apps, invoicing pages, payment portals, or any page with dollar amounts. 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 income 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 total side hustle income, your estimated income tax rate, and any business deductions. Select your filing status. Click "Calculate Tax Set-Aside" to see total tax, self-employment tax, income tax, net income, effective tax rate, and a suggested quarterly payment. Click "Extract from page" to scan the current page for income figures and auto-fill your total income. Use the export dropdown to choose your format—CSV or HTML (report). Click "Export" to download.

THE TECHNICAL MECHANISM

This script calculates self-employment tax at 15.3% of taxable income (the combined Social Security and Medicare rate for self-employed individuals). Income tax is calculated as taxable income multiplied by the user-provided tax rate. Taxable income is total income minus deductions. The total tax set-aside is the sum of self-employment tax and income tax. Net income is total income minus total tax. The effective tax rate is total tax divided by total income. The quarterly payment suggestion divides total tax by 4. The extraction function scans for dollar amounts and labels them with context (payment, income, earning, invoice, etc.). 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 income 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 tax calculations are estimates and do not constitute tax advice. Consult a tax professional for accurate filing. 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.