Annulus Area Calculator

To calculate the area of an annulus, square the outer radius (R²) and the inner radius (r²), subtract the square of the inner radius from the square of the outer radius, and then multiply the result by Pi (π). This gives you the area of the annulus.

Outer Radius (R): Inner Radius (r):

Annulus Area:

Formula: (Annulus Area = pi times (R^2 – r^2))

The Annulus Area Calculator helps you find the area of an annulus, which is the region between two concentric circles. The formula to calculate the area of an annulus is A = π(R² – r²), where R is the outer radius and r is the inner radius.

This calculator simplifies the process by allowing you to input the radii and get the result instantly. Whether you’re working with an annular ring, a cylinder, or determining the volume of an annulus, this tool is perfect for quickly solving geometry problems involving circular shapes.

Formula:

$A = \pi \times (R^2 − r^2)$

Variable	Meaning
A	Area of the annulus
R	Radius of the outer circle
r	Radius of the inner circle
π	Pi (approximately 3.14159)

Solved Calculations :

Example 1:

Given Values:

R = 10 cm (outer radius)
r = 6 cm (inner radius)

Calculation	Instructions
A = π × (10² − 6²)	Square both the outer and inner radii.
A = π × (100 − 36)	Subtract the inner radius squared from the outer radius squared.
A = π × 64	Multiply the result by Pi (π ≈ 3.14159).
A ≈ 3.14159 × 64	Perform the multiplication.
A ≈ 201.06 square centimeters	The result gives the area of the annulus.

Calculation	Instructions
A = π × (15² − 8²)	Square both the outer and inner radii.
A = π × (225 − 64)	Subtract the inner radius squared from the outer radius squared.
A = π × 161	Multiply the result by Pi (π ≈ 3.14159).
A ≈ 3.14159 × 161	Perform the multiplication.
A ≈ 505.66 square meters	The result gives the area of the annulus.

What is Annulus Area Calculator ?

An annulus is the region between two concentric circles, and its area can be found using the formula A = π(R² – r²). It makes it all easy by taking the outer radius R and inner radius r, providing an accurate result instantly.

This tool is essential for tasks like calculating the area of an annular ring, the annular area of a cylinder, or any similar geometric figure. For example, if you need to calculate the annulus area in square feet or meters, simply input the measurements, and the calculator does the rest.

Moreover, it can help solve for the volume of an annulus when dealing with 3D shapes like cylinders. The annulus volume formula is useful in fields such as engineering and construction, where accurate measurements are critical.

By using this calculator, you can quickly find the inner radius and outer radius of a ring, measure annular spaces, or determine the surface area for various projects. Whether you’re working with simple geometry or complex designs, this calculator ensures fast, accurate results for all your annular calculations.