Trades & Contractor Calculators

Practical calculation tools for electricians, drywallers, flooring installers, masons, plumbers, and movers. Sizing for wire gauge, tile, drywall sheets, concrete, HVAC BTUs, moving supplies, and pipe velocity.

Pipe Flow & Plumbing

Calculate water flow rate (GPM), velocity (ft/s), and internal volume in pipes.

Pipe & Flow Parameters

Nominal Pipe Diameter

Flow Rate (GPM)

Pipe Run Length (ft)

Flow Hydraulics

Flow VelocityAcceptable Cold (< 8 ft/s)

5.81 ft/s

Plumbing codes recommend under 5-8 ft/s

Water in Pipe

1.1 gal

Per 100 ft

2.3 gal

Plumbing Standard: Velocities over 8 ft/s can erode copper pipe walls, cause noisy pipes, and trigger water hammer when valves close rapidly.