GeoCalc is a free online geometry calculator covering 2D shapes, 3D shapes, and triangle mathematics. All calculations happen instantly in your browser — no sign-up, no installation, and no waiting.

Our Mission

Geometry is everywhere — from the floor tiles in your kitchen to the beams in a roof truss. Our mission is to make geometric calculations fast, accessible, and understandable for everyone, whether you're a student learning geometry for the first time, a carpenter cutting angles on a job site, or an engineer checking cross-sectional areas in a design. Every tool on GeoCalc is free, and every calculation runs locally in your browser.

What We Cover

GeoCalc covers a wide range of geometric calculations:

2D Shapes: Area, perimeter, and diagonal calculations for circles, rectangles, squares, triangles, trapezoids, parallelograms, ellipses, and regular polygons.
3D Shapes: Volume and surface area for spheres, cubes, rectangular prisms, cylinders, cones, and pyramids.
Triangle Tools: The law of sines, law of cosines, Heron's formula, right triangle solver, and angle calculations.
Circle Tools: Arc length, sector area, chord length, and inscribed angle calculations.

How the Tools Work

Every GeoCalc tool runs entirely in your browser using JavaScript's built-in Math library (Math.PI, Math.sqrt, Math.sin, Math.cos, etc.). When you enter your values, the result is computed on your device instantly — nothing is sent to a server. This means results appear in milliseconds, and the tools work even without an internet connection once the page has loaded.

Accuracy

All formulas are mathematically verified against standard geometric proofs. We use JavaScript's 64-bit floating-point arithmetic, which provides precision to approximately 15 significant decimal places — more than sufficient for any practical geometric calculation. Where formulas have known limitations (such as the triangle inequality), our tools validate inputs and display clear error messages rather than returning nonsensical results.

Who Uses GeoCalc

Our users include high school and college students checking homework, teachers preparing classroom examples, architects and engineers verifying quick calculations, woodworkers and metalworkers solving layout problems, and curious individuals who just want to know the area of an irregular shape. GeoCalc is built to serve all of these use cases with a clean, distraction-free interface.

Privacy

All calculations are performed client-side. We do not store your inputs or results. See our privacy policy for full details.

About GeoCalc