Area Of A Circle Calculator
Calculate the area of a circle from its radius, diameter, or circumference.
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Area
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Circumference
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Diameter
Recent Calculations
What Is Area Of A Circle?
The area of a circle is the amount of space enclosed within its boundary. It's one of the most fundamental geometric calculations.
Formula
A = πr², where r is the radiusExample
A circle with radius 5 has an area of π × 5² = 78.5398 square units.
Frequently Asked Questions
What is the formula for area of a circle?
A = πr², where r is the radius. You can also use A = πd²/4 with the diameter, or A = C²/(4π) with circumference.
What's the difference between area and circumference?
Area measures the space inside the circle (square units). Circumference measures the distance around the circle (linear units).