Regular Octagonal Prism Calculator

Calculate the volume, surface area, and other properties of a regular octagonal prism using its base edge length and height.

Using same unit as base edge

An octagonal prism is a three-dimensional shape with two parallel octagonal faces (bases) and eight rectangular faces. All angles in the regular octagon are 135°, making it a popular shape in architecture and design. The octagon combines the stability of a square with the smooth transitions of a circle.

Octagonal Prism Volume and Surface Area Calculator

Calculate the volume and surface area of an octagonal prism with our easy-to-use calculator. Learn about octagonal prism formulas, applications, and explore interactive examples.

An octagonal prism is a three-dimensional shape with two parallel octagonal faces (bases) connected by eight rectangular faces. This versatile shape is commonly used in architecture, columns, and structural design due to its combination of strength and aesthetic appeal.

Formula

Volume = 2a²(1 + √2)h
Surface Area = 8ah + 4a²(1 + √2)

Where:

  • a:length of one side of the octagonal base
  • h:height of the prism (distance between bases)

How to Calculate Octagonal Prism Volume

The volume is calculated by multiplying the area of the octagonal base (2a²(1 + √2)) by the height (h). The octagonal base area formula comes from dividing the octagon into eight equal triangles.

Understanding Surface Area

The surface area consists of two octagonal bases (2 × base area) and eight rectangular faces (8 × a × h). For a regular octagon, all sides are equal and all internal angles are 135°.

Real-World Applications

Octagonal prisms are commonly used in architecture (columns, towers), engineering (handles, tools), and construction (structural elements). Their shape provides a good balance between circular and square profiles.

Frequently Asked Questions

Why choose an octagonal shape over circular or square?

Octagonal shapes offer a good compromise between the strength of a circle and the practicality of a square. They're easier to manufacture than circles but provide better aerodynamics and aesthetics than squares.

How does an octagonal prism compare to other prisms?

An octagonal prism has eight rectangular faces connecting two parallel octagonal bases. This gives it more faces than hexagonal prisms (6) but fewer than decagonal prisms (10), offering a balance between complexity and functionality.

What are common uses for octagonal prisms?

Octagonal prisms are used in architecture (towers, columns), product design (pencils, handles), and engineering (structural supports). They're also common in traffic sign posts and light poles.