Compressed Air Pipe Sizing

Calculate the pressure drop in your pneumatic lines based on CFM flow.

Free Air Delivery (CFM)

System Pressure (PSI)

Pipe Length (Feet)

Pipe Internal Diameter (Inches)

Friction Pressure Drop

0 PSI

The Harris Formula for Compressed Air

Sizing pneumatic lines incorrectly leads to massive energy losses at the compressor. In the US, the Harris Formula is the standard empirical equation used by engineers to calculate friction loss in compressed air pipes.

Pressure Drop Equation: $$ P_d = \frac{0.1025 \times L \times Q^2}{P \times d^{5.31}} $$

Where:

$P_d$ = Pressure drop in PSI.
$L$ = Length of pipe in Feet.
$Q$ = Air flow in Cubic Feet per Minute (CFM).
$P$ = Initial absolute pressure in PSI (Gauge PSI + 14.7).
$d$ = Internal pipe diameter in Inches.