๐งช Column Volume Calculator
Calculate the internal volume of a chromatography column from its diameter and length โ or solve for either dimension.
Frequently asked questions
Why does column volume matter?
Column volume (CV) is the standard unit for describing gradient steps, equilibration volumes, and wash volumes in chromatography โ e.g. 'equilibrate with 5 CV of buffer' means 5 times your column's volume.
What's the difference between column volume and void volume?
Column volume (CV) is the total internal volume of the empty tube. Void volume (V0) is the retention volume of a completely unretained solute, which is smaller than CV because packing material occupies space โ typically V0 is about 0.65 to 0.70 times CV.
Does this work for prep-scale columns too?
Yes โ enter the ID and length of any packed column (analytical or preparative) in mm to get its volume in mL.
Accuracy & how this is derived
Derivation: Standard cylinder volume formula (V = pi r squared h), applied to column internal diameter and length, with unit conversion from mm3 to mL (1 mL = 1000 mm3).
Validated against: Basic geometry โ no empirical calibration required; matches column volume specifications published by chromatography column manufacturers.
โ ๏ธ For educational and research support only โ verify critical results independently before use in regulated, clinical, or publication-bound work.
โ Last updated: July 2026 ยท Report an error
Calculating chromatography column volume
Column volume (CV) is calculated as the volume of a cylinder โ pi times the square of the radius times the length โ converted from cubic millimeters to milliliters. It is the standard reference unit chromatographers use to describe equilibration, wash, and elution volumes independent of the specific column dimensions in use, which makes protocols portable between columns of different sizes as long as they're expressed in CV rather than absolute mL.