Justin Ha

Solo maker of CalcSpin

About

I build small web tools on my own. CalcSpin is my free collection of calculators and decision tools in Korean, English and German.

Badges

Tastemaker

Maker History

CalcSpinFree calculators and decision tools, no sign-up needed
Nov 2026

🎉

Joined Product HuntNovember 11th, 2026

Forums

•

3h ago

CalcSpin - Free calculators and decision tools, no sign-up needed

Small, fast browser tools: US state paycheck calculators, an EU261/UK261 flight delay compensation calculator, tip calculator, spin the wheel, random picker and QR codes. No sign-up, mobile friendly, and the math shows its sources.