Column & Void Volume Calculator

Calculate the empty geometric volume of an HPLC column, as well as the estimated void volume ($V_m$) and void time ($t_0$) based on column dimensions and packing porosity.

mm
mm
mL/min
Typically ~0.68 for fully porous spherical particles.
Mathematical Formulas
1. Empty Column Volume ($V_c$)

Calculates the geometric volume of the empty cylinder.

$V_c = \pi \times r^2 \times L$

Where $r$ = radius in cm (ID/20), $L$ = length in cm (L/10).

2. Void Volume ($V_m$)

The actual volume occupied by the mobile phase, accounting for particle porosity.

$V_m = V_c \times \epsilon$

Where $\epsilon$ = total column porosity.

3. Void Time ($t_0$)

The time it takes for an unretained solvent/molecule to elute.

$t_0 = \frac{V_m}{F}$

Where $F$ = Flow Rate (mL/min).