Flow Rate (Chromatography) Calculator
Convert linear velocity to volumetric flow rate for any chromatography column diameter, and calculate volumes and time for column volume-based steps.
Results
What is it?
In chromatography, linear velocity (cm/h) is a scale-independent measure of how fast buffer moves through the resin bed. Volumetric flow rate (mL/min) depends on column cross-sectional area. Linear velocity is used in method development so protocols transfer directly between columns of different diameters.
How to use
Enter the column inner diameter, the linear velocity from your method, the packed column volume (CV), and the number of CVs for your current step (e.g. 5 CV wash). The calculator outputs volumetric flow rate and the total volume and time for that step.
Example scenario
A 1.6 cm diameter column (area = 2.01 cm2) at 150 cm/h linear velocity: flow = 2.01 x 150 / 60 = 5.03 mL/min. With a 50 mL column, a 5 CV equilibration step = 250 mL, taking 250/5.03 = 49.7 minutes. Scaling up to a 5 cm diameter column: area = 19.6 cm2, flow = 49 mL/min at same linear velocity.
Pro tip
Scale-up rule: keep linear velocity constant (not volumetric flow rate) to preserve separation performance. If doubling the column diameter (4x area), multiply the flow rate by 4 to maintain the same linear velocity. Monitor backpressure -- exceeding the resin pressure limit compresses the bed and ruins separation. Typical affinity resins: 100-300 cm/h max. Ion exchange: 150-400 cm/h.