Equivalent Length of Pipe Calculator

Equivalent length is the length of pipe with diameter and friction factor having the same energy loss as a fitting


Equivalent length of pipe calculation is mobile-device-friendly as of January 20, 2014

Solve for:  Pipe Diameter, D: 
Moody Friction Factor, f: 
Minor Loss Coefficient, K: 
Equivalent Length, Leq
© 2014 LMNO Engineering,  Research, and Software, Ltd. www.LMNOeng.com

Units: f and K are unit-less. D and Leq have the same units. For instance: If D is in meters, then Leq is in meters. If D is in inches, then Leq is in inches. If D is in ft, then Leq is in ft.

Equivalent length equation:  Leq = K D / f

If rectangular duct, compute D from:  D = 4 A / P

where A=Area of duct and P=Perimeter of duct. Equations from references listed at Discussion and References for Closed Conduit Flow.


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LMNO Engineering, Research, and Software, Ltd.
7860 Angel Ridge Rd.   Athens, Ohio 45701  USA   Phone and fax: (740) 592-1890
LMNO@LMNOeng.com    http://www.LMNOeng.com

August 25, 2015: Made text fields show 8 significant figures rather than 16. Calculation still uses double precision internally.

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Related calculations:

Pipe Network

Friction factor

Minor loss coefficients

Unit Conversions

Other information:

Trouble printing?


Discussion and References for Closed Conduit Flow