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Perimeter vs. Circumference: What's the Difference?

Edited by Janet White || By Harlon Moss || Updated on November 8, 2023
The perimeter is the total distance around a two-dimensional shape, while circumference specifically refers to the distance around a circle.

Key Differences

The perimeter is a term used to describe the total distance around any two-dimensional geometric shape, such as a rectangle, square, or triangle. Circumference, however, is a term that applies specifically to the distance around a circle or circular object. It is the equivalent of the perimeter but for round shapes.
In practical applications, one might measure the perimeter of a garden to determine how much fencing is needed. On the other hand, one might measure the circumference of a pipe to ensure a proper fit for materials that need to wrap around it, such as insulation or decals.
The concept of perimeter can be extended to include irregular shapes and even non-geometric areas, such as the boundary of a property. Circumference remains strictly within the realm of circles and does not apply to shapes that do not have a constant distance from a central point.
In essence, the perimeter is a more general concept used in various branches of mathematics and everyday measurements, whereas circumference is a specific type of perimeter used exclusively for circles and circular objects.

Comparison Chart


The total length around a two-dimensional shape
The distance around a circle


Any two-dimensional shape
Only circular shapes

Geometric Use

Used for polygons and irregular shapes
Used exclusively for circles

Real-world Example

Measuring fencing for a rectangular yard
Measuring the edge of a circular pool cover

Perimeter and Circumference Definitions


The outermost limits or boundary of an area or object.
The soldiers guarded the perimeter of the camp.


The distance around the edge of a circle.
The circumference of the circular garden was 30 feet.


A fortified boundary that protects or defines an area.
The perimeter was secured to prevent any breaches.


The outer boundary, especially of a circular area.
The circumference of the base of the cylinder was measured.


The continuous line forming the boundary of a closed geometric figure.
They calculated the perimeter of the square field.


The measurement around the middle of something, especially a body part.
The tailor took the circumference of her waist for the dress.


The boundary of a specific area or surface.
The dogs were allowed to roam within the perimeter of the backyard.


The length of such a boundary.
The wheel's circumference was exactly two meters.


The sum of the lengths of the sides of a polygon.
For her math homework, she found the perimeter of various polygons.


A line enclosing a circular space.
The children drew the circumference of the circle with a compass.


A closed line bounding a plane area.


The boundary line of a circle.


The length of such a line.


The boundary line of an area or object.


The outer limits of an area.


A defended boundary protecting a military position.


Can the terms perimeter and circumference be used interchangeably?

No, perimeter refers to any shape, while circumference is specific to circles.

Is the circumference always larger than the perimeter?

Not necessarily; it depends on the size of the respective shapes.

How do you measure the perimeter of a rectangle?

Add the lengths of all four sides of the rectangle.

Why do we need to calculate the circumference?

Calculating circumference is important for things like fitting circular objects together.

Is calculating the perimeter important in real life?

Yes, it's essential for tasks like buying fencing material or flooring.

Does the complexity of a shape affect how you measure its perimeter?

Yes, more complex shapes may require more detailed measurements.

Can you find the perimeter of a circle?

The term perimeter is not typically used for circles; circumference is the correct term.

Is the circumference a type of perimeter?

Yes, it is the perimeter of a circle.

Are perimeter and circumference both considered linear measurements?

Yes, both are linear measurements despite the shape they are measuring.

When do you need to know the perimeter?

When you need the measure of the boundary of any flat, two-dimensional shape.

Can the formula for circumference be applied to an ellipse?

No, an ellipse has a different formula for calculating the distance around it.

Can circumference be measured in three dimensions?

No, circumference is also a two-dimensional measurement, despite the circle being represented in three dimensions.

When do you need to know the circumference?

When dealing with the distance around a circle or circular object.

Can both perimeter and circumference be measured in the same units?

Yes, both are measured in linear units, such as meters or feet.

Can you have a shape with an infinite perimeter but finite circumference?

No, shapes with a finite circumference will also have a finite perimeter.

Are perimeters always flat measurements?

Yes, perimeter is a two-dimensional measurement.

What's a common mistake when measuring perimeter or circumference?

A common mistake is using the wrong formula or not measuring accurately.

Does the complexity of a shape affect its circumference?

Circumference is only used for circles and is always measured the same way.
About Author
Written by
Harlon Moss
Harlon is a seasoned quality moderator and accomplished content writer for Difference Wiki. An alumnus of the prestigious University of California, he earned his degree in Computer Science. Leveraging his academic background, Harlon brings a meticulous and informed perspective to his work, ensuring content accuracy and excellence.
Edited by
Janet White
Janet White has been an esteemed writer and blogger for Difference Wiki. Holding a Master's degree in Science and Medical Journalism from the prestigious Boston University, she has consistently demonstrated her expertise and passion for her field. When she's not immersed in her work, Janet relishes her time exercising, delving into a good book, and cherishing moments with friends and family.

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