Pipe Flow Rate and Velocity Calculator

Fluid Flow Design and Engineering

Calculator will determine Pipe Flow Rate and Velocity required based on Head Loss, h_L, and Frictional Pressure Drop, DP_f, for given flow rate, Q, pipe diam., D, pipe length, L, pipe roughness, e, and fluid properties, r & m.

Moody Friction Factor Equation

Pipe Roughness Values

Preview: Pipe Flow Rate and Velocity Calculator

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NOTE: This is an iterative calculation, because an assumed value of Q is used to start the calculations. If the final calculated value of Q is different from the assumed value, then the assumed value of Q should be replaced with the calculated value of Q, leading to a new calculated value for Q. This should be repeated as many times as necessary to get the calculated value for Q to be the same as the assumed value. This iteration typically converges rather rapidly.

This spreadsheet shows only the final assumed and calculated values of Q (when they are equal). If the initial assumed value of Q was 1.5 cfs, then subsequent calculated and assumed values for Q, leading to the final solution are as follows:

Assumed Q, cfs	Calculated Q, cfs
1.5	0.85
0.85	0.83
0.83	0.83

Related:

• Pipe Diameter Based on & Friction Factor Calculator
• Pipe Friction Head Loss, Friction Pressure, and Frictional Pressure Equations and Calculator