Geometry

Torus Volume Calculator (Donut Volume)

Compute the volume of a torus from major and minor radii. For donuts, inner tubes, magnetic confinement rings, and O-rings.

Truncated Pyramid Surface Area Calculator

Compute square-base truncated pyramid surface area from top edge, bottom edge, and height. For hopper plating, plinth finishing, and dam facing.

Octagon Area Calculator (regular)

Find the area of a regular octagon from its side length. Returns apothem, long diagonal, and perimeter. Used for stop signs and gazebos.

Octahedron Volume Calculator (Regular)

Compute regular octahedron volume from edge length. For d8 dice, mineral specimens, and double-pyramid crystal forms in geology and crystallography.

Regular Polygon Calculator (any number of sides)

Calculate area, perimeter, apothem, and circumradius of any regular n-sided polygon from its side length. Works from triangle (n=3) to 100+.

Torus Surface Area Calculator (Donut)

Compute torus surface area from major and minor radii. For donut frosting, O-ring coating, and toroidal fuel tank fabrication.

Octagon Perimeter Calculator (regular)

Compute the perimeter of a regular octagon from its side length. Returns area, apothem, and across-flats distance. Multiple units.

Sphere Volume Calculator

Compute sphere volume from radius or diameter. For balls, planets, water spheres, and balloon capacity. With unit conversion to liters.

Spherical Cap Volume Calculator

Compute spherical cap volume from sphere radius and cap height. For dome enclosures, fish-eye lens domes, and partially filled spherical tanks.

Hexagon Area Calculator (regular)

Calculate the area of a regular hexagon from its side length. Also returns apothem, long diagonal, and perimeter. Multiple units.

Hexagon Perimeter Calculator (regular)

Compute the perimeter of a regular hexagon from its side length. Returns area, apothem, and long diagonal too. Multiple units.

Icosahedron Volume Calculator (Regular)

Compute regular icosahedron volume from edge length. For d20 dice, virus capsid modeling, and geodesic dome geometry foundations.

Sphere Surface Area Calculator

Compute sphere surface area from radius. For ball wrapping, planet surface estimates, water droplets, balloons, and biological cell sizing.

Cube Volume Calculator

Compute the volume of a cube from its side length. For storage boxes, sugar-cube counts, and ice-cube freezer calculations.

Pentagon Area Calculator (regular)

Calculate the area of a regular pentagon from its side length. Also returns apothem, circumradius, and perimeter in multiple units.

Pentagon Perimeter Calculator (regular)

Compute the perimeter of a regular pentagon from its side length. Returns apothem, area, and diagonal as a bonus. Multiple units.

Semicircle Area Calculator

Compute the area of a semicircle (half a circle) from its radius or diameter. For half-moon windows, dome floor plans, and arches.

Trapezoidal Prism Volume Calculator

Compute trapezoidal prism volume from the two parallel sides, trapezoid height, and prism length. For retaining walls, swimming pool layouts, and ramps.

Cube Surface Area Calculator

Compute cube surface area from side length. For gift wrapping, painting boxes, sheet metal cube fabrication, and packaging design.

Hexagonal Pyramid Volume Calculator

Compute hexagonal pyramid volume from base edge and height. For honeycomb-style roofs, hexagonal tent pavilions, and decorative pyramidal forms.

Kite Area Calculator (quadrilateral)

Calculate kite area from its two diagonals. A kite has two pairs of adjacent equal sides. Includes side-length calculation. Multiple units.

Kite Perimeter Calculator (quadrilateral)

Compute kite perimeter from its two pairs of adjacent equal sides (a and b). A kite has two short sides and two long sides. Multiple units.

Pentagonal Prism Volume Calculator

Compute the volume of a pentagonal prism from base edge and length. For five-sided columns, decorative pencils, and crystal-form geology.

Square Pyramid Volume Calculator

Compute the volume of a square-based pyramid from base side and height. For Egyptian-style pyramid layouts, tent volumes, and roof attics.

Stadium Shape Area Calculator

Compute the area of a stadium (discorectangle) — a rectangle with semicircular ends. For tracks, oval rugs, and pill-shaped layouts.

Trapezoid Area Calculator

Compute trapezoid area from the two parallel sides (a and b) and the perpendicular height. Used for retaining walls, gables, and irregular plots.

Cylinder Volume Calculator

Compute cylinder volume from radius and height. For water tanks, pipe contents, paint cans, and silos. With unit conversion to liters and gallons.

Ellipsoid Surface Area Calculator

Compute ellipsoid surface area using Knud Thomsen's approximation. For rugby ball coating, planet surface estimates, and egg shell sizing.

Rhombus Area Calculator

Compute rhombus area from its two diagonals. A rhombus has four equal sides (a diamond shape). Multiple units supported.

Trapezoid Perimeter Calculator

Compute trapezoid perimeter from its four side lengths. Two parallel sides (a, b) plus two legs (c, d). Multiple units supported.

Circular Segment Perimeter Calculator

Compute the perimeter of a circular segment — chord length plus arc length. For arched openings, tunnel sections, and partial fills.

Cylinder Surface Area Calculator

Compute cylinder surface area from radius and height. For can labels, paint estimation on columns, and sheet metal cylinder fabrication.

Parallelepiped Volume Calculator

Compute the volume of a right parallelepiped from base sides, included angle, and height. For oblique boxes, crystal forms, and lean-to structures.

Rhombus Perimeter Calculator

Compute rhombus perimeter from one side or from the two diagonals. All four sides of a rhombus are equal. Multiple units.

Octahedron Surface Area Calculator (Regular)

Compute regular octahedron surface area from edge length. For d8 dice plating, crystal specimen mounting, and dual-pyramid sculpture finishes.

Parallelogram Area Calculator

Calculate parallelogram area from base and perpendicular height. Works for any parallelogram including rhombus and rectangle. Multiple units.

Triangular Prism Surface Area Calculator

Compute triangular prism surface area from triangle dimensions and length. For Toblerone wrappers, roof shingles, and tent fabric calculations.

Parallelogram Perimeter Calculator

Compute parallelogram perimeter from its two adjacent side lengths. Includes the rectangle and rhombus as special cases. Multiple units.

Pentagonal Prism Surface Area Calculator

Compute the surface area of a regular pentagonal prism from edge length and prism length. For five-sided column wraps and decorative finishes.

Triangular Prism Volume Calculator

Compute the volume of a triangular prism from base, triangle height, and prism length. For rooflines, ramps, and Toblerone-shaped boxes.

Ellipse Area Calculator

Compute the area of an ellipse from its two semi-axes a and b. Returns approximate perimeter via Ramanujan formula. Multiple units.

Sector Perimeter Calculator

Compute the perimeter of a circular sector — two radii plus the arc length. Useful for trim, edging, and fan-shaped layouts.

Truncated Cone Volume (Conical Frustum)

Compute the volume of a truncated cone (frustum) from top radius, bottom radius, and height. For buckets, lampshades, and tapered tanks.

Ellipse Perimeter Calculator (Ramanujan)

Compute ellipse perimeter using the Ramanujan approximation from the two semi-axes a and b. Also returns area and eccentricity.

Hexagonal Pyramid Surface Area Calculator

Compute hexagonal pyramid surface area from base edge and height. For pavilion roof shingles, six-sided spire cladding, and decorative finishes.

Truncated Cone Surface Area Calculator (Frustum)

Compute truncated cone surface area from both radii and height. For lampshade fabric, bucket sheet metal, and tapered tank coating.

Circle Area Calculator

Find a circle area from its radius. Also returns circumference and diameter. Inputs in mm, cm, m, km, inches, feet, yards, or miles.

Spherical Cap Surface Area Calculator

Compute the curved surface area of a spherical cap from sphere radius and cap height. For dome paint coverage and lens dome fabrication.

Triangular Pyramid Volume Calculator

Compute the volume of a triangular pyramid (tetrahedron) from base triangle area and height. For pyramid tea bags and origami forms.

Platonic Solids Calculator

Calculate volume, surface area, and all three radii of any Platonic solid. Tetrahedron, cube, octahedron, dodecahedron, icosahedron — all 5 in one tool.

Regular Dodecahedron Calculator

Calculate volume, surface area, inradius, and circumradius of a regular dodecahedron from its edge length. Uses exact golden ratio formulas.

Triangular Pyramid Surface Area Calculator

Compute triangular pyramid surface area from equilateral base edge and slant height. For tetrahedral packaging, dice, and pyramid tea bags.

Annulus Area Calculator (Ring Area)

Compute the area of an annulus (ring) from outer and inner radii. For washers, gaskets, race tracks, and roundabout cross-sections.

Hemisphere Volume Calculator

Compute the volume of a hemisphere — half a sphere — from its radius. For mixing bowls, dome buildings, and half-tank capacity.

Hexagonal Prism Calculator

Calculate the volume, lateral surface area, and total surface area of a regular hexagonal prism. Enter the side length and height to get results.

Hexagonal Pyramid Calculator

Find the volume, slant height, lateral surface area, and total surface area of a regular hexagonal pyramid from base side length and height.

Isosceles Triangle Area Calculator

Compute isosceles triangle area from the base and the two equal sides. Returns area, height, and perimeter. Multiple units.

Isosceles Triangle Perimeter Calculator

Compute isosceles triangle perimeter from the base and the two equal legs. Validates triangle inequality. Multiple units.

Pentagon Calculator

Calculate the area, perimeter, diagonal, apothem, and circumradius of a regular pentagon from its side length. Works in any unit — meters, cm, or inches.

Regular Tetrahedron Calculator

Calculate volume, surface area, height, inradius, and circumradius of a regular tetrahedron from its edge length. All five properties with exact formulas.

Right Cone Calculator

Calculate the volume, slant height, lateral surface area, and total surface area of a right circular cone. Enter radius and height to get all results.

Right Square Pyramid Calculator

Find the volume, slant height, lateral surface area, and total surface area of a right square pyramid from base side length and height.

Dodecahedron Surface Area Calculator (Regular)

Compute regular dodecahedron surface area from edge length. For d12 dice plating, decorative architectural finishes, and pentagonal-face modeling.

Equilateral Triangle Perimeter Calculator

Compute the perimeter of an equilateral triangle from just one side. Returns area, height, and perimeter together. Multiple units.

Hemisphere Surface Area Calculator

Compute hemisphere surface area — curved dome plus flat circular base. For dome paint, bowl coating, and half-sphere enclosure design.

Capsule Volume Calculator (Pill Shape)

Compute the volume of a capsule — a cylinder with hemispherical end caps. For pills, propane tanks, and pressure vessel design.

Equilateral Triangle Area Calculator

Calculate the area of an equilateral triangle from just its side length. Returns area, height, perimeter, and inradius in any common unit.

Hexagonal Prism Surface Area Calculator

Compute hexagonal prism surface area from edge length and prism length. For pencil finishing, nut coating, and honeycomb panel cladding.

Cone Surface Area Calculator

Compute cone surface area from radius and height. For party hat patterns, ice cream cone wrappers, and traffic cone material estimation.

Regular Tetrahedron Volume Calculator

Compute regular tetrahedron volume from a single edge length. For 4-sided dice (d4), pyramid tea bags, and crystal structure modeling.

Right Triangle Perimeter Calculator

Compute right triangle perimeter from the two legs. Returns hypotenuse via Pythagoras and total perimeter. Multiple units.

Sector Area Calculator

Compute the area of a circular sector (pizza-slice shape) from radius and central angle. Degrees or radians, with multiple unit selections.

Annulus Perimeter Calculator

Compute the total perimeter of an annulus — outer circumference plus inner circumference. For ring trim, gasket edges, and track borders.

Capsule Surface Area Calculator (Pill Shape)

Compute capsule surface area — cylinder side plus sphere. For pill coatings, propane tank painting, and pressure vessel material.

Cone Volume Calculator

Compute cone volume from radius and height. For ice-cream cones, traffic cones, conical tanks, party hats, and silo tops.

Parallelepiped Surface Area Calculator

Compute right parallelepiped surface area from base sides, included angle, and height. For oblique box finishing and crystal-form surface analysis.

Right Triangle Area Calculator

Calculate area of a right triangle from its two legs. Also returns hypotenuse via the Pythagorean theorem. Multiple units supported.

Annulus Calculator

Calculate area and perimeter of an annulus — the ring between two concentric circles. Enter outer and inner radius with unit select for instant results.

Capsule Calculator

Calculate volume and surface area of a capsule — a cylinder capped with two hemispheres. Enter the radius and cylinder height for instant results.

Conical Frustum Calculator

Calculate volume and surface area of a conical frustum (truncated cone) from top radius, bottom radius, and height. Includes slant height formula.

Pyramid Frustum Calculator

Calculate volume and surface area of a pyramid frustum (truncated square pyramid) from top side, bottom side, and height. Includes slant height formula.

Rectangular Prism Surface Area Calculator (Box)

Compute box surface area from length, width, height. For paint estimation, wrapping paper, and packaging design with three different edges.

Regular Tetrahedron Surface Area Calculator

Compute regular tetrahedron surface area from a single edge length. For d4 dice coating, pyramid tea bag fabric, and tetrahedral kite sails.

Stadium Shape Calculator

Calculate area and perimeter of a stadium shape — a rectangle with semicircular ends. Enter the radius and straight-section length for instant results.

Torus Calculator

Calculate the volume and surface area of a torus (donut shape) from major and minor radii. Uses Pappus centroid theorem formulas with a worked example.

Triangle Perimeter Calculator

Compute the perimeter of any triangle from its three sides. Validates the triangle inequality. Multiple units supported.

Hexagonal Prism Volume Calculator

Compute hexagonal prism volume from edge length and prism length. For pencils, nuts and bolts, honeycomb cells, and hex-shaped containers.

Rectangular Prism Volume Calculator (Box)

Compute the volume of a rectangular box from length, width, and height. For shipping, aquariums, storage cabinets, and rooms.

Triangle Area Calculator (base and height)

Calculate triangle area from base and perpendicular height. Works for any triangle — right, obtuse, scalene, isosceles, equilateral. Multiple units.

Circular Segment Area Calculator

Compute the area of a circular segment (the region between a chord and the arc it cuts off). Includes horizontal-tank fill scenarios.

Ellipsoid Volume Calculator

Compute ellipsoid volume from three semi-axes a, b, c. For rugby balls, planet shapes, eggs, and general elongated 3D forms.

Rectangle Perimeter Calculator

Compute rectangle perimeter from length and width. Use it for baseboards, fence lengths, and frame trim. Multiple units supported.

Rectangular Pyramid Surface Area Calculator

Compute rectangular pyramid surface area from base length, width, and height. For hipped roof shingles on non-square buildings.

Rectangle Area Calculator

Compute rectangle area from length and width in mm, cm, m, km, inches, feet, yards, or miles. Use it for flooring, paint coverage, and fabric cuts.

Rectangular Pyramid Volume Calculator

Compute a rectangular-base pyramid volume from length, width, and height. For hipped roofs on non-square buildings and tapered hoppers.

Stadium Shape Perimeter Calculator

Compute the perimeter of a stadium shape — two straight sides plus a full circle of curve. Used for tracks, oval rugs, and pill outlines.

Trapezoidal Prism Surface Area Calculator

Compute trapezoidal prism surface area from trapezoid dimensions, slant sides, and prism length. For retaining wall finishing and channel lining.

Hollow Cylinder Surface Area Calculator

Compute the total surface area of a hollow cylinder — outer side, inner side, and two annulus end faces. For painting pipes and tube coatings.

Icosahedron Surface Area Calculator (Regular)

Compute regular icosahedron surface area from edge length. For d20 dice plating, geodesic dome panels, and virus capsid modeling.

Hollow Cylinder Volume Calculator (Pipe Wall)

Compute the wall-material volume of a hollow cylinder from outer radius, inner radius, and length. For pipes, tubes, and sleeves.

Square Perimeter Calculator

Compute the perimeter of a square from its side length. Useful for fencing, framing, and edge trim. Multiple units supported.

Truncated Pyramid Volume Calculator (Square Frustum)

Compute square-base truncated pyramid (frustum) volume from top edge, bottom edge, and height. For hopper bottoms, plinth blocks, and dam cross-sections.

Dodecahedron Volume Calculator (Regular)

Compute regular dodecahedron volume from edge length. For d12 dice, soccer ball cell geometry, and pentagonal-face Platonic solid modeling.

Semicircle Perimeter Calculator

Compute the perimeter of a semicircle — half a circle plus the diameter. Used for arch trim, half-moon window molding, and curved patios.

Square Area Calculator

Calculate the area of a square from its side length. Works in mm, cm, m, km, inches, feet, yards, and miles with instant conversion.

Square Pyramid Surface Area Calculator

Compute square pyramid surface area from base edge and height. For Egyptian pyramid stone, tent fabric, and roof shingle estimation.

Area of Shapes Calculator

Calculate the area of any 2D shape — circle, rectangle, triangle, trapezoid, parallelogram, ellipse, and more. Supports metric and imperial units.

Circumference Calculator

Calculate the circumference and area of a circle from the radius or diameter. Also find the radius or diameter from a known circumference.

Triangle Solver

Solve any triangle — find all sides and angles from any combination of known values. Supports SSS, SAS, ASA, AAS, and SSA using Law of Sines and Cosines.

Volume of Shapes Calculator

Calculate the volume of any 3D shape — sphere, cylinder, cone, rectangular prism, pyramid, and more. Includes unit conversion for all common units.

Surface Area Calculator

Calculate surface area of cubes, rectangular prisms, spheres, cylinders, cones, and pyramids. Returns total and lateral area in square inches, cm, and meters.

Circle Calculator

Enter radius, diameter, circumference, or area of a circle and calculate all other measurements instantly. Returns all four values with full formulas shown.