Geometry Calculators

Free geometry tools for circles, rectangles, right triangles, triangles, cylinders and spheres — diameter, circumference, area, perimeter, diagonal, Pythagorean theorem, Heron's formula, volume and surface area. Every calculator is free, instant and private.

Circle Calculator

Diameter, circumference and area from the radius.

Pythagorean Theorem

Find the hypotenuse or a missing leg of a right triangle.

Triangle Area Calculator

Area from base and height, or from three sides with Heron's formula.

Rectangle Calculator

Area, perimeter and diagonal from length and width.

Cylinder Calculator

Volume and total surface area from radius and height.

Sphere Calculator

Volume and surface area from the radius.