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Annulus Calculator

Enter outer and inner radii to calculate the geometry of an annulus.

Area = 201.06193π(R² − r²)
4Ring width
62.831853Outer circumference
37.699112Inner circumference

How to use this Annulus Calculator

Calculate ring area, width, and inner and outer circumferences. Enter your values above and the result is calculated directly in your browser. No account is required.

Fast answer, clear inputs

This tool is built around one job: give the answer quickly without forcing a signup or hiding the result. Related tools are linked nearby when the next calculation or conversion is useful.