Bench tools for builders · est. 2010

Size it right before you buy it

Free calculators that answer the questions every robot build starts with: which motor, which battery, which gear ratio. No guesswork, no forum-thread archaeology — and every tool shows the formula it uses.

Open the Motor Sizing Calculator →

Tools

New tools are added regularly. Bookmark this page — your build will thank you.

Why these tools exist

Most robot builds fail at the shopping cart, not the workbench. A motor that stalls on carpet, a battery that dies in eight minutes, a gearbox that turns your "fast" robot into a slow one — all of these are math problems that take thirty seconds to solve before you spend money.

Each tool on this site does one calculation properly, explains the engineering behind it in plain language, and tells you what class of part to look for. Use them, check the math, build better robots.