🧰 Free ToolBase Chinese

Pipe Flow Calculator

Enter pipe diameter, velocity and fluid type — calculate flow rate (GPM/CFM), Reynolds number and flow regime

💧 Fluid Engineering

💧 Pipe Parameters

Presets:
Flow Rate

📊 Details

Cross Section
Velocity
Reynolds Number
Flow Regime

FAQ

How do I calculate pipe flow rate?

Flow rate = cross-sectional area × velocity. First calculate pipe area (π×ID²/4), then multiply by velocity to get CFM. For water, GPM = CFM × 7.48.

What is Reynolds number?

Reynolds number (Re) is a dimensionless value that predicts flow regime. Re = velocity × diameter / kinematic viscosity. Re < 2300 = laminar (smooth), Re > 4000 = turbulent (chaotic, higher energy loss), 2300-4000 = transitional.

What's the difference between pipe materials?

Steel: rougher interior, higher friction, used for large industrial pipes. Copper: smooth interior, used for home water supply. PVC: smoothest, lowest friction, used for pools and irrigation. This calculator provides ID reference but does not calculate friction loss.

What's the recommended velocity for home water pipes?

Copper supply lines: 4-8 ft/s. Below 4 ft/s risks sediment buildup; above 8 ft/s causes water hammer noise and accelerated erosion. A 3/4" copper line at 6 ft/s delivers ~8 GPM.

🔗 Related Tools