Geometry Calculator

Calculate area, perimeter, surface area, or volume for common shapes.

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Area
78.539816
Circumference
31.415927

How area, perimeter, and volume are calculated

This geometry calculator helps calculate area, perimeter, surface area, and volume for common shapes. It is useful for schoolwork, renovation estimates, material planning, packaging, and everyday space calculations.

Use consistent units before calculating. Mixing centimeters, meters, inches, or feet in the same formula can produce incorrect area or volume results.

Formula or logic

  • Rectangle area = length × width
  • Circle area = π × radius²
  • Rectangular prism volume = length × width × height
  • Cylinder volume = π × radius² × height

Example

If a floor is 4 meters long and 3 meters wide, the area is 12 square meters. For materials, it is common to add extra allowance for cuts and waste.

Common questions

What is the difference between area and perimeter?

Area measures the size of a surface, while perimeter measures the total length around the edge.

Are volume and surface area the same?

No. Volume measures space inside a 3D object; surface area measures the total outside area.

How precise should π be?

For everyday estimates, 3.14 is usually enough. More precise work can use more digits.

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