## Related Tools

Find another flow measurement calculator by clicking on the required answer which coincides with the input parameters you already know.

vol flow | mass flow | flow speed | vol | mass | time | |
---|---|---|---|---|---|---|

area |
flow speed | vol flow | ||||

dia |
flow speed | vol flow | ||||

w x h |
flow speed | vol flow | ||||

time |
vol | mass | vol flow | mass flow | ||

vol |
time | density | vol flow | |||

mass |
time | density | mass flow | |||

density |
mass flow | vol flow | mass | vol | ||

flow speed |
area, dia |

- Calculate volumetric flow rate from flow velocity and pipe diameter
- Calculate flow speed from volumetric flow rate and pipe diameter
- Calculate mass flow rate from volumetric flow rate and density
- Convert volumetric flow rates to other units
- Convert diameter into to other units
- Convert flow speed to other units

## User Guide

This tool will calculate the internal diameter of a round pipe or duct that a substance is flowing through, from the rate of volumetric flow and the speed of the flow. A range of conversion values for flow and diameter will also be displayed for each set of input parameters entered.

### Formula

The formula used by this calculator to calculate the internal pipe or duct diameter is:

ø = (Q / (v · π))^{½} · 2

Derived from:

A = Q / v

A = π · r²

r = ø / 2

#### Symbols

- Q = Volume flow rate
- v = Flow velocity
- A = Cross-sectional area
- r = Radius
- ø = Diameter

n.b. This formula assumes uniform flow conditions within the entire cross-sectional area of pipe, without any friction losses near to surfaces.

### Volumetric Flow Rate Required

Enter the volumetric quantity which will flow through per unit of time.

### Flow Velocity Measured

Enter the speed that the substance is moving through the pipe or duct.

### Diameter Calculation

This is the internal diameter of a pipe or duct that would be required for a substance moving at the specified speed and volumetric flow rate.