Circumference Calculator

Circumference Calculator

Calculate the circumference (perimeter) of a circle from radius, diameter, or area. Get comprehensive results with visual diagrams and related circle properties.

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From Radius
C = 2πr
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From Diameter
C = πd
From Area
C = 2π√(A/π)

Calculate Circumference from Radius

Formula:
Circumference = 2π × Radius
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Circumference
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Radius
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Diameter
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Area
r Circumference = 2πr C
π (Pi) ≈ 3.14159
The ratio of circumference to diameter for any circle

How to Use the Circumference Calculator

The Circumference Calculator determines the perimeter of a circle using any known circle property. Choose your input method from radius, diameter, or area, enter the value with your preferred units, and get instant results including all related circle measurements. The calculator uses the mathematical constant π (pi) to provide precise calculations and displays comprehensive circle properties for complete reference.

Understanding circumference is crucial in various applications including construction, engineering, manufacturing, and everyday measurements. Whether you're calculating the length of material needed to wrap around a circular object, determining the distance traveled by a wheel in one rotation, measuring pipe circumferences, or solving geometry problems, this calculator provides accurate results with clear visual representations to enhance your understanding of circular mathematics.

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From Radius
C = 2π × 5cm = 31.42cm

Multiply radius by 2π

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From Diameter
C = π × 10cm = 31.42cm

Multiply diameter by π

From Area
C = 2π√(78.5/π) = 31.42cm

From area to circumference via radius