EVERYDAY CLARITY
Annulus Calculator
What is the area of a ring between two circles? Enter the values below to calculate the result.
Your result
area
length^2
Result for the values shown.
Calculations run in your browser.
What to enter
| Input | Meaning and units |
|---|---|
| Outer or sphere radius (length) | Enter the radius, which is half the diameter. |
| Radius (length) | Enter the radius, which is half the diameter. |
Understanding your result
Read area (length^2) in the units and model stated on this page. The formula area=pi*(R*R-r*r) defines the relationship; measurement accuracy and model applicability are separate from numerical precision.
Common mistakes
- Entering the diameter where the radius is requested.
Check your calculation
- Use the worked example as a known reference case, then change one input at a time and check the direction and units of the response.
Calculation checks, sources and review limits
What is the area of a ring between two circles?
What is the area of a ring between two circles? Enter the values below to calculate the result.
Common uses
- What is the area of a ring between two circles
How it works
area=pi*(R*R-r*r)
Worked example
Enter Outer or sphere radius: 5 length; Radius: 3 length. Results: area: 50.26548245743669 length^2.