Calculate flow from area and velocity or volume and time, or reverse-solve velocity and pipe diameter. Convert L/min, gpm, cfm, m3/h, and mass flow.

Use the open internal cross section and mean speed through it.

Optional mass flow

Blank omits mass flow; use density at the flow measurement conditions.

Volumetric Flow Rate Formula

The following equation is used to calculate the volumetric flow rate of a fluid moving through a pipe.

Q = A × vₘean
  • Where Q is the volumetric flow rate (m³/s)
  • A is the cross-sectional area (m^2)
  • v_mean is the cross-sectional mean flow speed normal to the area (m/s)

To calculate volumetric flow rate, multiply open cross-sectional area by mean flow speed normal to it. The other modes use Q = V/t, V = Qt and t = V/Q. Entering density optionally adds mass flow at the measurement conditions.

Volumetric Flow Rate Definition

A volumetric flow rate is the total volume of fluid moving through a cross-sectional area per unit of time.

Volumetric Flow Rate Example

How to calculate volumetric flow rate?

  1. First, determine the cross-sectional area.

    Measure the area the fluid is moving through.

  2. Next, determine the flow velocity.

    Calculate or measure the cross-sectional mean flow speed.

  3. Finally, calculate the volumetric flow rate.

    Calculate the VFR using the equation above.

FAQ

What is volumetric flow rate?

Volumetric flow rate is the rate at which a given volume of fluid flows through the opening of an area. In other words, it measures how much volume passes through a point per unit of time.

What is flow velocity?

In Q = A × v_mean, flow speed is averaged over the open cross section and taken normal to it; local particle speeds can differ.