Hey 👋 I built Circle Calculator because every circle tool I found online did exactly one thing — area, or circumference — and sent me elsewhere the moment I needed anything more. So I built 14 calculators into one place: the basics, plus arcs, chords, sectors, tangents, circle equations, a 3-point circle solver, triangle-circle relationships, ellipse comparisons, and a couple of odd, specific ones I built for myself — a Minecraft block-circle generator, and a bolt-circle PCD calculator for anyone doing mechanical/machining work. Every calculator comes with a guide explaining the formula and a worked example, so it's not just a black-box number — you can see how you got there. It's free, no login, no paywall. Would love feedback on which calculator is most useful, what's missing, and what's confusing. Also curious if anyone actually uses the Minecraft one — that was a fun tangent to build.

Circle Calculator

Circle math for students, machinists, and Minecrafters.

Circle math for students, machinists, and Minecrafters.