Since 2010
RoboticsFAQ.com exists to answer the questions every robot build starts with — which motor, which battery, which gear ratio, which servo — with actual engineering math instead of guesswork.
We build free, browser-based calculators for hobby and student robotics. Each tool does one calculation properly, shows the formulas it uses so you can verify the math yourself, and explains in plain language what class of part your result points to. Alongside the tools, our blog publishes practical guides that go one level deeper into the engineering behind each calculator.
Hobbyists building their first wheeled robot, students preparing competition machines, teachers looking for classroom-ready references, and anyone who has ever bought a motor that hummed instead of moved. If you've spent an evening digging through forum threads for a torque formula, this site was made for you.
Every calculator on this site states its assumptions, applies honest deratings (like usable battery capacity and gearbox efficiency), and errs on the conservative side — because a robot that works beats a spec sheet that flatters. Where results depend on values that vary in the real world, such as rolling resistance or motor efficiency, we say so and show the numbers we use.
RoboticsFAQ is free to use. It is supported by advertising and by affiliate links: when we link to parts (motors, batteries, servos), some links may earn us a small commission at no extra cost to you. Affiliate relationships never change the results our calculators produce — the math is the math.
Found an error in a formula, want a new calculator, or have feedback? We genuinely want to hear it — see the contact page.