Perimeter of a Pentagon Calculator

Find the perimeter of a regular pentagon from one side length, or an irregular pentagon by summing all five side lengths.

Input

All five sides are equal. Enter one side length.

Result

Enter values and click Calculate.

Summary

Find the perimeter of a regular pentagon from one side length, or an irregular pentagon by summing all five side lengths.

How it works

  1. Choose Regular or Irregular mode using the tabs.
  2. Regular: enter the single side length and click Calculate.
  3. Irregular: enter all five side lengths (a through e) and click Calculate.
  4. The result panel shows the perimeter and full step-by-step working.
  5. Click Reset to clear the form and start over.

Use cases

Frequently Asked Questions

Last updated: 2026-05-23 · Reviewed by Nham Vu