Building My Own IBKR Tax Calculator

Live version: https://bgtax.vercel.app

I built this as a hobby project for my own use. I was tired of dealing with Interactive Brokers statements manually whenever tax season came around, so I made a tool that handles the boring part for me.

I kept it intentionally small and practical:

• React 19 + Vite
• MUI v9
• decimal.js for precise calculations
• fully client-side processing

Privacy mattered to me from the start. The data stays in the browser. There is no backend, no upload step, no account, and no tracking.

I used Claude to scaffold the first version quickly. That saved time on setup and boilerplate and let me focus on the actual problem. After that, I refactored the code heavily by hand - especially the parsing logic, calculation flow, and overall architecture.

That was the useful part of the process for me. AI helped me move fast, but the project only became solid after I cleaned it up properly.

This is still a personal project, not a polished commercial product. But it solves a real problem for me, and that is usually the best reason to build something in the first place.

Repository: https://github.com/lilistw/lilistw.github.io

Informational only - not tax advice.