Area & Volume Calculator
Area and volume formulas for the common shapes - circle, square, rectangle, triangle, sphere, cylinder, cone, and more. Just pick a shape, enter the dimensions you have, and get the result without looking up a formula.
How to use
- Pick the shape you're working with from the list.
- Fill in whatever dimensions you have - radius, length, height, base, etc.
- Click Calculate and get area or volume instantly. Units are whatever you entered, squared or cubed.
Related tools:
Area and volume formulas are taught in school but easy to forget when you actually need them. The circle area formula (pi x r squared) gives the space inside a circle; the sphere volume formula (4/3 x pi x r cubed) seems counterintuitive at first but follows directly from integrating circles. This calculator covers the shapes you actually encounter: rectangles, triangles, circles, cubes, cylinders, cones, and spheres.
Practical uses come up more often than expected. Painting a room means calculating wall area. Filling a cylindrical tank means knowing its volume. Cutting a circular tablecloth or laying out a garden bed with a specific shape all need these formulas. The calculator handles the arithmetic once you have the measurements.
Frequently Asked Questions
What units does the calculator use?
It works with whatever units you input - cm, m, inches, feet. Area output is in those units squared (e.g. m squared) and volume is in units cubed. For mixed units, convert to a single unit first.
What is the difference between area and surface area?
Area refers to a flat 2D surface. Surface area is the total area of all faces of a 3D object. A cube with side 5 has volume 125 cubic units but surface area 150 square units (6 faces of 25 each).
How do I calculate the area of an irregular shape?
Break it into recognisable shapes (rectangles, triangles, semicircles) and add them up. For complex curves, planimeter tools or numerical integration (like counting grid squares) are needed.