Geometry Calculators

Free geometry tools for circles, rectangles, right triangles, triangles, cylinders, spheres, cones, trapezoids and square footage — diameter, circumference, area, perimeter, diagonal, Pythagorean theorem, Heron's formula, volume, slant height, surface area and conversions to square meters and acres. 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.

Cone Calculator

Volume, slant height, and lateral and total surface area from radius and height.

Trapezoid Calculator

Area and median (midsegment) from the two parallel sides and height.

Triangle Calculator

Solve any triangle from 3 values — SSS, SAS, ASA, AAS and the ambiguous SSA case.

Square Footage Calculator

Area in square feet, square meters and acres from length and width in ft, in, yd or m.

Circumference Calculator

Circumference of a circle from radius, diameter, area, or circumference itself.