## Hplc column volume calculator

The following equations are for the novice chromatographer. More advanced calculations can be found on the system suitability and pressure-flow pages.

1. Calculation of total column volume (also used for calculating bed volume)

2. Calculation of empty column linear flow rate from volumetric flow rate

3. Calculation of volumetric flow rate from empty column linear flow rate

**1. Calculation of total column volume (also used for calculating bed volume):**

Where: *V* = calculated column volume*r* = column radius*L* = length of the column (or packed bed)

**2. Calculation of empty column linear flow rate from volumetric flow rate:**

Where:*u* = Linear flow rate (cm/hr)*F* = volumetric flow rate (mL/hr) [multiply mL/min x 60 min/hr]*r* = column radius (cm)

**3. Calculation of volumetric flow rate from empty column linear flow rate**

Where:*F* = volumetric flow rate (mL/hr) [divide by 60 min/hr to get mL/min]*u* = Linear flow rate (cm/hr)*r* = column radius (cm)

#### The term column volume, typically abbreviated CV, is a value used to help determine separation quality and loading capacity. But how can this concept and its definition be better understood? Bob Bickler explains it all on the Flash Purification Blog.

Some chemists think the internal volume of the cartridge *without* packing material inside is the column volume. While useful in determining scale-up factors, the empty column’s volume is not the CV. The CV of any column or cartridge is the volume inside of a packed cartridge *not* occupied by the media. This volume includes both the interstitial volume (volume outside of the particles) and the media’s own internal porosity (pore volume). Combined, the two volumes constitute 70% to 80% of the packed cartridge’s volume. Of course this means that the media only occupies 20% to 30% of the space in the cartridge.

**Hplc column volume calculator **