Math · 12 calculators
Area, perimeter, volume and surface area of 2D shapes and 3D solids, plus the Pythagorean theorem.
Geometry
Solve any triangle from three sides (SSS): area with Heron’s formula, perimeter, angles, heights and triangle type.
Area = √(s(s − a)(s − b)(s − c)), s = (a …
Also called triangle area calculator · herons formula calculator
Geometry
Enter a circle’s radius, diameter, circumference or area and get all the others instantly.
A = πr²
Also called circle area · circumference calculator
Geometry
Area, perimeter and diagonal of a rectangle from its length and width, with the aspect ratio.
A = l × w
Also called rectangle area · area of rectangle
Geometry
Calculate the area, perimeter and diagonal of a square from any one of side, area, perimeter or diagonal.
A = s²
Also called square area · area of a square
Geometry
Find the area of a trapezoid (trapezium) from its two parallel sides and height, plus the median length.
A = ½ (a + b) h
Also called trapezium area · area of trapezoid
Geometry
Area, perimeter and diagonals of a parallelogram from two sides and the angle between them.
A = a·b·sin θ = base × height
Also called parallelogram area · area of parallelogram
Geometry
Area, perimeter, interior angle, apothem and circumradius of any regular polygon from the number of sides and side length.
A = n·s² / (4·tan(π/n))
Also called polygon area · hexagon area
Geometry
Volume, surface area and circumference of a sphere from its radius or diameter.
V = 4/3 πr³
Also called sphere volume · volume of a sphere
Geometry
Volume, surface area and space diagonal of a cube from the edge length.
V = a³
Also called cube volume · volume of a cube
Geometry
Volume, lateral area and total surface area of a cylinder from radius and height — plus capacity in liters for cm inputs.
V = πr²h
Also called cylinder volume · volume of cylinder
Geometry
Volume, slant height and surface area of a right circular cone from its radius and height.
V = ⅓πr²h
Also called cone volume · volume of a cone
Geometry
Find the missing side of a right triangle with a² + b² = c² — solve for the hypotenuse or either leg.
a² + b² = c²
Also called pythagoras calculator · hypotenuse calculator
| Triangle | Area = √(s(s − a)(s − b)(s − c)), s = (a + b + c)/2 |
|---|---|
| Circle | A = πr² · C = 2πr · d = 2r |
| Rectangle | A = l × w · P = 2(l + w) · d = √(l² + w²) |
| Square | A = s² · P = 4s · d = s√2 |
| Trapezoid | A = ½ (a + b) h |
| Parallelogram | A = a·b·sin θ = base × height |
| Regular Polygon | A = n·s² / (4·tan(π/n)) · interior angle = (n − 2)·180°/n |
| Sphere | V = 4/3 πr³ · A = 4πr² |
| Cube | V = a³ · A = 6a² |
| Cylinder | V = πr²h · A = 2πr(r + h) |
Area = ½ × base × height. Use the triangle area calculator for that method, or enter all three sides here to use Heron’s formula.
Only for right triangles. For other triangles use the law of cosines, which reduces to Pythagoras when the angle is 90°.