Enter the total GPM and the cross-sectional area of flow into the calculator to determine the velocity.

GPM to Velocity Formula

The following equation is used to calculate the Velocity from GPM.

V = GPM / 7.481 / A / 60 
  • Where V is the velocity (ft/s)
  • GPM is the gallons per minute
  • A is the cross-sectional area of flow (ft^2)

To calculate the velocity from gallons per minute, divide the GPM by 7.481, divide again by the cross-sectional area of flow, then finally, divide by 60.

How to Calculate Velocity From GPM?

Example Problem:

The following example outlines the steps and information needed to calculate Velocity from GPM.

First, determine the gallons per minute. In this example, the gallons per minute is found to be 250.

Next, determine the cross-sectional area of flow. In this case, the cross-sectional area of flow is measured to be 3ft^2.

Finally, calculate the velocity from GPM using the formula above:

V = GPM / 7.481 / A / 60

V = 250 / 7.481 / 3 / 60

V = .185