Plumbing Tools

Pipe Size Calculator

Calculate water pipe diameter for plumbing systems based on fixture units, flow rate, and velocity. Supports copper, PVC, and PEX piping.

Plumbing System Parameters

Total Fixture Units

Pipe Material

Flow Rate (GPM)

Max Velocity (FPS)

Available Pressure (PSI)

Pipe Length (feet)

Application

                                Minimum Pipe Size
                                -

Actual Velocity 0 FPS

Estimated Flow Rate 0 GPM

Pressure Loss 0 PSI

Pipe ID (inside dia) 0 in

Cross-Sectional Area 0 sq in

Friction Factor -

Est. Pipe Cost/100ft $0

GPM ≈ FU^0.5 × 2.5 (approx)

Velocity = GPM × 0.408 ÷ ID²

Max Velocity: 8 FPS cold, 5 FPS hot

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