Area of Regular Octagon Calculator

Enter the side length to calculate the area of a regular octagon instantly.

Side Length

About Area of Regular Octagon

The Area of Regular Octagon Calculator is a fast, reliable, and easy-to-use tool that helps you calculate the area of any regular octagon using just the side length. Whether you're a student working on math homework, a designer planning geometric layouts, or a professional in architecture or engineering, this calculator delivers accurate results in seconds.

What Is a Regular Octagon?

A regular octagon is an eight-sided polygon where all sides and angles are equal. Regular octagons are often found in architectural design, flooring patterns, and even traffic stop signs. While calculating its area manually can be time-consuming, this calculator makes it simple with a precise mathematical formula.

Formula for Area of a Regular Octagon:

Area = 2(1 + √2) × a²

Where a is the length of one side.

Example Calculation:

If the side length a = 4 cm, then:

Area = 2(1 + √2) × 4² ≈ 77.25 cm²

✅ So, the area of the regular octagon is approximately 77.25 square centimeters.

Features of the Calculator:

One-Click Solution – Calculate instantly using side length.

All Units – Supports cm, m, ft, in, and more.

Accurate & Fast – Reliable results in seconds.

Cross-Device – Works on desktop, tablet, and mobile.

Ideal For

Education – Geometry and trigonometry assignments.

Architecture – Construction layouts and designs.

Home Design – Tile layouts and decorative planning.

Teaching – Useful for math educators and demonstrations.

Easily calculate the area of any regular octagon with this calculator — your go-to geometry tool for fast, accurate, and hassle-free results!