About hakaru

hakaru(計る) is a Japanese word meaning “to measure” or “to calculate.” We build free online tools that help you figure things out — quickly, accurately, and without friction.

Why We Exist

Most online calculators and tools are either buried behind signups, cluttered with ads, or built with decade-old interfaces. We think useful tools should be free, fast, and pleasant to use.

Every tool on hakaru.io is designed to solve a specific problem — whether you're calculating your self-employment taxes, figuring out your freelance rate, or converting text between formats. No account needed. No data collected. Just tools that work.

How We Build

Our tools are built with modern web technology and designed for speed. Everything runs in your browser — your data never leaves your device. We use AI to enhance certain tools (like generating personalized insights), but the core calculations are always transparent and verifiable.

New Tools Every Week

We're constantly adding new tools based on what people actually search for. If you have a suggestion for a tool we should build, we'd love to hear it.