Use this annulus area calculator to quickly calculate area of annulus using inner and outer radius. Perfect for annulus area formula tasks.
A = area of annulus
R = outer radius
r = inner radius
π ≈ 3.14159
| Inner Radius | Outer Radius | Annulus Area |
|---|---|---|
| 3 | 5 | 50.265482 |
| 4 | 7 | 113.097336 |
| 2 | 6 | 100.530966 |
| 1 | 4 | 47.123890 |
| 5 | 10 | 235.619449 |
1. Square the outer radius (R²).
2. Square the inner radius (r²).
3. Subtract r² from R².
4. Multiply the result by π to get the annulus area.
This annulus area calculator automatically computes results with up to six decimal places. Useful for students, engineers, and designers needing precise calculate area of annulus results.
• An annulus is the region between two concentric circles.
• Annuli appear in gears, washers, and circular plates.
• Understanding annulus area is important in engineering and architecture.
• The area is proportional to the difference of squares of radii.
• Annuli concepts are used in optics and mechanics.