Plumbing Pipe Size Calculator

Calculate pipe size from flow rate and velocity. Pressure drop estimation. Common pipe size reference.

Flow Rate (GPM)

Desired Velocity (ft/s)

Pipe Material

Pipe Length (feet)

Number of Fittings (elbows, tees)

Recommended velocity: 5-8 ft/s for supply lines. Max 4 ft/s for drain lines. Higher velocity increases noise and wear.

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