The volume specified as available for a capsule fill, normally expressed in millilitres.
Also called: capsule volume; nominal capsule volume; body volume; fill capacity.
Body fill volume and total internal volume
Powder-fill capacity, liquid-fill capacity and total internal capsule volume can be listed separately, even for the same shell size. Check which quantity a capacity chart reports before using the number.
A larger total internal volume does not mean that the whole figure is available as the intended powder dose. Do not combine a body-volume value from one chart with a total-volume value from another as if they were equivalent.
For an estimate, multiply the usable fill volume in mL by the formulation’s relevant fill density in g/mL, then multiply grams by 1,000 to express the mass in mg. Volume is space; mg is mass.
The density must describe the powder state relevant to the filling process. A loose bulk-density result and a tapped-density result are not interchangeable promises of the mass a machine will deliver.
Estimated fill mass (mg) = fill volume (mL) × fill density (g/mL) × 1,000
The calculation can check whether a volume-and-density claim is internally consistent. It cannot demonstrate stable dosing, the final locked condition or actual fill-weight variation. Those are separate questions for the intended formulation and filling arrangement.