Is this calculation free and private?

Yes, 100% of calculations execute locally in your web browser. No inputs or personal data are stored or transmitted.

What do I need to enter?

Just Water Flow Rate, Pipe Inside Diameter, Total Pipe Run Length and Material. Every field has a sensible default you can start from.

Is my data uploaded anywhere?

No. The calculation runs in your browser with JavaScript — nothing you type is sent to a server or stored.

Does it work on a phone?

Yes. The layout adapts to small screens and needs no app or signup.

Water Pipe Friction Loss & Pressure Drop Calculator

Calculate plumbing water velocity (fps), friction head loss (PSI & feet), and pressure drop using the Hazen-Williams hydraulic equation.

100% free
Private in browser
No signup
No watermarks

Water Flow Rate (Gallons per Minute GPM)

Pipe Inside Diameter (Inches, e.g. 0.75 for 3/4")

Total Pipe Run Length (Feet)

Material (1=PEX C=150, 2=Copper C=140, 3=PVC C=150, 4=Galvanized C=100)

Total Friction Pressure Loss (PSI)

17.19

Friction Head Loss (Feet)

39.7

Water Velocity (Feet per Second fps)

8.7

Pressure Loss per 100 Feet (PSI/100ft)

17.2

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About Water Pipe Friction Loss & Pressure Drop Calculator

Calculate plumbing water velocity (fps), friction head loss (PSI & feet), and pressure drop using the Hazen-Williams hydraulic equation. Enter Water Flow Rate, Pipe Inside Diameter and Total Pipe Run Length and the tool works out Total Friction Pressure Loss, Friction Head Loss and Water Velocity straight away. Everything runs in your browser, so your data never leaves your device.

How to use Water Pipe Friction Loss & Pressure Drop Calculator

Enter Water Flow Rate, Pipe Inside Diameter and Total Pipe Run Length.
Adjust the remaining options (Material) to match your case.
Read Total Friction Pressure Loss, Friction Head Loss and Water Velocity in the results panel — copy or download what you need.

Key features

Shows Total Friction Pressure Loss (PSI)
Shows Friction Head Loss (Feet)
Shows Water Velocity (Feet per Second fps)
4 adjustable inputs, results update as you type
No signup, no limits

Frequently asked questions

Is this calculation free and private?: Yes, 100% of calculations execute locally in your web browser. No inputs or personal data are stored or transmitted.
What does the Water Pipe Friction Loss & Pressure Drop Calculator give me?: It works out Total Friction Pressure Loss, Friction Head Loss, Water Velocity and Pressure Loss per 100 Feet, updating live as you change the inputs.
What do I need to enter?: Just Water Flow Rate, Pipe Inside Diameter, Total Pipe Run Length and Material. Every field has a sensible default you can start from.
Is my data uploaded anywhere?: No. The calculation runs in your browser with JavaScript — nothing you type is sent to a server or stored.
Does it work on a phone?: Yes. The layout adapts to small screens and needs no app or signup.

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