QuickGradeCalc Online

I'm the founder and developer of QuickGradeCalc, a free set of grade calculators for students and teachers, built with Next.js. I started it because working out the score you need on a final exam, or grading a stack of tests, shouldn't take a spreadsheet. Today it includes a final grade calculator, a percentage-to-letter-grade converter, and a quick grader where you tap +1 wrong for each missed question and see the percentage and letter grade instantly. No sign-up needed. I write about building the site, including technical SEO and privacy-first design, on my developer blog. Feedback is always welcome, especially on how grading works at your school. Website: https://www.quickgradecalc.online/