What this calculator does
Calculate the area and boundary lengths of a ring between two concentric circles.
How it works
The calculator evaluates area = π(R² − r²). Inputs are checked before calculation, and invalid values such as zero denominators or out-of-range selections produce a clear error instead of a misleading result.
Input query strings and outputs
Use an input name in this page’s URL as ?name=value, and join additional inputs with &. Portable shared links may instead use the compact ?ac= state parameter.
Input query strings
2-
?outerRadius=Outer radius RNumber · Required · Default: 10
-
?innerRadius=Inner radius rNumber · Required · Default: 6
Outputs
4-
areaAnnulus areaNumber · Primary output
-
outerCircumferenceOuter circumferenceNumber
-
innerCircumferenceInner circumferenceNumber
-
widthRing widthNumber
Inputs and results
The inputs are Outer radius R, Inner radius r. Results include Annulus area, Outer circumference, Inner circumference, Ring width.