Perimeter Calculator

Perimeter Calculator

Calculate polygon perimeter or circle circumference from the entered measurements.

Last updated: June 2026 | By Patchworkr Team

Result
15
Perimeter

What is Perimeter?

Perimeter is the total distance around a shape.

Polygon: sum of all side lengths
Circle: 2 pi r

How to Use

1. Choose polygon or circle.

2. Enter the side lengths or radius.

3. Read the live perimeter or circumference result.

Worked Example

For side lengths 4, 6, 4, 6:

perimeter = 4 + 6 + 4 + 6 = 20

FAQ

Does polygon input need commas?

No. Spaces or commas both work.

What if I enter fewer than three sides?

The tool rejects it because a polygon needs at least three sides.

Can circle input use decimals?

Yes, as long as the radius is a positive real number.

Is circumference a perimeter?

Yes. For circles, the perimeter is called circumference.

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