# Friction Loss Formula

Learn how to solve fire hose friction loss with the friction loss formula. Below, you'll find the formula and an example of solving the friction loss formula. We also provided friction loss problems for you to solve, alonw with a link to the answer of each problem. You can also create your own problems and check your answers with the **Friction Loss Calculator**

**FL = C * (Q / 100) ^2 * L / 100**

FL = Friction loss in PSI

C = Friction loss Coefficient (From Table)

Q = Flow rate in GPM

L = Hose length

#### Example:

**What 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)

GPM (**Q**) = 150 GPM

Length (**L**) = 200 feet

FL = C * (Q / 100) ^2 * L / 100

69.75 = 15.5 * (150 / 100)^2 * 200 / 100

**Answer:** **There's 69.75 PSI friction loss for a 200 foot of 1.75 inch hose with 150 GPM.**

Coefficient Table | |

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 |

**Practice solving friction loss equations:**

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**