Enter the column diameter and the linear velocity into the calculator to determine the flow rate. This calculator is designed to help chromatographers in the field of analytical chemistry to optimize their high-performance liquid chromatography (HPLC) systems.

Agilent Flow Rate Formula

The following formula is used to calculate the flow rate in an HPLC system:

FR = (π * (CD / 10)^2 / 4) * LV


  • FR is the flow rate (mL/min)
  • CD is the column diameter (mm)
  • LV is the linear velocity (cm/min)

To calculate the flow rate, use the column diameter to find the cross-sectional area of the column and multiply it by the linear velocity.

What is Flow Rate in HPLC?

The flow rate in high-performance liquid chromatography (HPLC) is the volume of mobile phase (solvent) that passes through the column per unit of time. It is a critical parameter that influences the separation efficiency, analysis time, and resolution of the chromatographic system. The flow rate is determined by the column dimensions and the desired linear velocity of the mobile phase.

How to Calculate Flow Rate?

The following steps outline how to calculate the flow rate for an HPLC system:

  1. First, determine the column diameter (CD) in millimeters.
  2. Next, determine the desired linear velocity (LV) of the mobile phase in centimeters per minute.
  3. Use the formula from above to calculate the flow rate (FR) in milliliters per minute.
  4. Finally, enter the values into the calculator to verify the flow rate.

Example Problem:

Use the following variables as an example problem to test your knowledge.

Column diameter (CD) = 4.6 mm

Linear velocity (LV) = 1 cm/min