How this calculator works
Subtract the inner circular cross-section from the outer one, then multiply by height. This gives wall material, while the inner cylinder gives bore capacity. Their sum is the full outer envelope. Radius, diameter and thickness inputs are alternative descriptions of the same cross-section. Material-volume reverse modes isolate the missing dimension. The cylinder has a constant section along its length; there are no end caps. A zero inner radius is accepted as the solid-cylinder limit.
Formula
Material V = π(R²-r²)h = π(R-r)(R+r)h; bore = πr²h; envelope = πR²h; wall t=R-r. Reverse h=V/[π(R²-r²)], R=sqrt(r²+V/(πh)), r=sqrt(R²-V/(πh)).
Worked example
Outer radius 5 m, inner radius 3 m and height 2 m give wall thickness 2 m. Material volume is 32π m³ and bore volume is 18π m³. Their sum, 50π m³, matches the outer solid cylinder.
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Frequently asked questions
Is the material volume the liquid capacity?
No. Material volume occupies the wall. Bore capacity is the empty space inside, shown separately.
Is wall thickness the difference of diameters?
It is half the difference of diameters, or the difference of radii. Subtracting the full diameter difference would double the wall thickness.
Does this include closed ends?
No. It is an open-ended annular cylinder. End plates, fittings and changing wall sections require additional volume.