Geometry Calculators
Last updated: October 2026
Triangle Area Calculator
Calculates the area of any triangle from two sides and the included angle (the SAS formula): A = ½·a·b·sin(C).
Circle Area Calculator
Calculate the area of a circle from its radius with A = πr², with the diameter and circumference shown alongside.
Circle Arc and Sector Calculator
Calculate the arc length, sector area, or circular segment area for a given radius and central angle in degrees or radians.
Circle Calculator
Enter any one circle measurement, radius, diameter, circumference or area, and get any other.
Sphere Calculator
Find a sphere's volume, surface area, radius or diameter from any one of those measurements.
Prism Calculator
Find the volume, total surface area, or lateral surface area of any prism — triangular, rectangular, or polygonal — from its base dimensions and height.
Rectangle and Square Calculator
Find the area, perimeter, diagonal or aspect ratio of a rectangle or square from its length and width.
Regular Polygon Area Calculator
Calculate the area, perimeter, and interior angles of any regular polygon — from equilateral triangles to dodecagons — given just the side length.
Cone Calculator
Compute the volume, lateral surface area, total surface area, or slant height of a right circular cone from its base radius and height.
Cylinder Surface Area and Volume Calculator
Compute the volume, lateral area, or total surface area of solid, hollow, or open-top cylinders.
Ellipse Area and Circumference Calculator
Calculate the area, circumference (perimeter), eccentricity, and focal distance of an ellipse using its semi-major and semi-minor axes.
Rectangle Calculator (Find the Missing Side)
Find a rectangle's area, perimeter, diagonal or missing side from any two known values: length and width, a side and the area, a side and the perimeter, or a side and the diagonal.
Rectangular Prism Calculator
Calculate the volume, surface area, and space diagonal of a rectangular prism (box) from its length, width, and height.
Regular Polygon Calculator
Instantly calculate interior angles, exterior angles, area, and perimeter of any regular polygon.
Cone and Pyramid Calculator
Compute volume, total surface area, or slant height for cones, square pyramids, and triangular pyramids.
Pythagorean Theorem Calculator
Solve a right triangle with a² + b² = c².