Annulus (Ring) Area Calculator
Enter the outer and inner radius of a ring shape (annulus) to calculate the area of the ring itself.
Annulus (Ring) Area Calculator
Calculate the area of an annulus (ring shape) — the area between two concentric circles.
This calculator provides an estimate for general informational purposes only. It is not a substitute for professional financial, mechanical or engineering advice.
An annulus is the ring-shaped region between two circles sharing the same center; its area is simply the larger circle's area minus the smaller circle's area.
Example
- With the default values shown above, this calculator returns: Annulus Area ≈ 201.06.
Frequently Asked Questions
What is the formula?
Annulus Area = π × (Outer Radius² − Inner Radius²), which is simply the big circle's area minus the small circle's area.
What is this used for?
Annulus area calculations come up for washers, pipes, gaskets, tracks, and any ring-shaped or donut-shaped object.