Show HN: Final Grade Calculator – Calculate what you need on your final exam (finalgradecalculator.app)

  Hi HN! I built this grade calculator to solve a problem I had in college.

  Every semester before finals, I'd spend time with a spreadsheet calculating "what grade do I need on
  the final to get an A in this class?" I figured students still deal with this, so I made a simple
  tool.

  Features:
  - Final grade calculator (what score you need)
  - Weighted grade calculator (multiple assignments with different weights)
  - Grade converter (percentage ↔ letter grade ↔ GPA)
  - Real-time calculations, works offline after first load

  Tech stack: Next.js 15 (App Router), TypeScript, Tailwind CSS. Fully static site, deployed on Vercel.

  The code is open source (link in footer). I focused on making it fast and accessible – no tracking,
  no accounts, just a calculator.

  Happy to answer questions about the implementation or get feedback on features!