Learn how to solve friction loss (fire hose pressure loss) with the friction loss formula. Below, you'll see an example of solving the friction loss formula. We have also provided several friction loss problems for you to solve & provided a links to the answer for each problem. If you create your own problems, you can check your answers with the Friction Loss Calculator
FL = C * (Q / 100) ^2 * L / 100What is the friction loss for a 200 foot of 1.75 inch fire hose flowing 150 GPM of water?
Coefficient (C) for 1.75" hose is 15.5 (See Table 1)Answer: There's 69.75 PSI friction loss for a 200 foot of 1.75
inch hose with 150 GPM.
Answer verified in the friction loss calculator
Table 1 Friction Loss Coefficient 

Hose Diameter  Coefficient 
0.75 inch  1100 
1 inch  150 
1 ¼ inch  80 
1 ½ inch  24 
1 ¾ inch  15.5 
2 inch  8 
2 ½ inch  2 
3 inch  0.677 
3 ½ inch  0.34 
4 inch  0.2 
4 ½ inch  0.1 
5 inch  0.08 
6 inch  0.05 
What is the friction loss of 200 feet of 1.75" hose with 200 gpm? Answer 200' of 1.75" @ 200 GPM
What is the friction loss of 150 feet of 2" hose with 500 gpm? Answer 150' of 2" @ 500 GPM
What is the friction loss of 100' of 1" hose with 100 gpm?Answer 100' of 1" @ 100 GPM
What is the friction loss of 300' of 3" hose with 600 gpm?Answer 300' of 3" @ 600 GPM
What is the friction loss of 400' of 3" hose with 800 gpm?Answer 400' of 4" @ 800 GPM
Verify your own friction loss problems with Friction Loss Calculator
Friction Loss Explained
Friction loss occurs when water passes through a hose. Hose length, diameter, and GPM (volume) all affect friction loss. As water passes through a hose, friction between the water and the inside surface of the hose causes turbulence, which slows the water. The results in a PSI drop (pressure loss) at the other end of the hose. The higher the gpm passing through a hose, the more turbulence and friction loss will result.
Additional Fire Engine Operator Tools
The FireDepartment.net staff have designed additional fire training tools:
FireDepartment.net strives to provide fire departments & firefighters with quality tools. But, the user takes full responsibility for the information contained above. Use at your own risk!