Pi Day Calculators
Pi Day hosts a focused collection of 20+ math calculators centred around geometry, financial math, and academic grading — a mix of high-school and college-level reference tools.
Geometry & Shapes(12)
Arc Length Calculator
Computes the arc length of a circular sector from radius and central angle.
Area of a Rectangle Calculator
Calculates the area of a rectangle from its width and height.
Area of a Trapezoid Calculator
Calculates the area of a trapezoid from the lengths of its parallel sides and height.
Circle Calculator
Finds circumference, diameter, area, or radius of a circle given any one of these values.
Circumference Calculator
Calculates the circumference of a circle from its radius or diameter.
Ellipse Calculator
Computes the area, perimeter, and focal points of an ellipse from its semi-axes.
Golden Rectangle Calculator
Calculates dimensions of a rectangle that follows the golden ratio for design and architecture work.
Hexagon Calculator
Computes side length, area, perimeter, and apothem of a regular hexagon.
Octagon Calculator
Calculates side, area, perimeter, and apothem of a regular octagon.
Right Triangle Calculator
Solves for sides and angles of a right triangle given any two known values.
Surface Area Calculator
Calculates the surface area of common 3D shapes — sphere, cube, cylinder, cone, and others.
Volume Calculator
Computes the volume of common 3D shapes from their dimensions.