Drainage Calculator by Pipe Size

Our drainage calculator was developed in partnership with the University of Minnesota Extension to assist you in the preliminary design and understanding of your drainage needs. We encourage you to contact your local design professional or contractor for more specific design guidance and criteria.

These calculations are based on the Manning’s Roughness ASAE EP 260.3 Plastic Tubing Drainage Chart and should be used for estimating purposes only. Consult a Water Table Management Professional for design criteria information

? = Definition

Enter the Diameter of the pipe (inches):
Enter the Grade (%): Grade
%
 

(see below)


  Q, Flow Flow Velocity Velocity
  c.f.s. g.p.m acre - in./24 hrs. ft./sec.
Single-Wall
Dual-Wall

 
Acres Drained
 
Drainage Coefficient (in: /24 hours) Drainage
 
1/8"
1/4"
3/8"
1/2"
3/4"
1"
Single-Wall
Dual-Wall

Calculate by Acreage