Shapes & spaces

Isoperimetric quotient from area and perimeter calculator

Compare the compactness of a plane region with the circle of the same perimeter.

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Behind the numbers

How this calculation works

Compare the compactness of a plane region with the circle of the same perimeter.

THE FORMULAQ=4πA/P²

A worked example

A unit square has quotient π/4.

Good to know

A value above one indicates inconsistent measurements for an ordinary plane region.

Read the result

Compare the compactness of a plane region with the circle of the same perimeter.

The primary result is labeled “Compactness quotient”. Keep the input definitions in view when comparing this result with another method.

Try a related calculation

A value above one indicates inconsistent measurements for an ordinary plane region.

For a related exercise, try the circle calculator.

A few questions, answered

How can I check the default inputs by hand?

A unit square has quotient π/4.

Which rule does this calculator apply?

Q=4πA/P²

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