1/2 Inch Pipe Calculator & Complete Guide
Calculate flow rates, capacity, and sizing for 1/2 inch pipes. Complete guide to 1/2" pipe specifications, applications, and flow capacity for copper, PEX, PVC, and CPVC.
1/2 inch pipe is one of the most common sizes used in residential plumbing systems, typically serving as branch lines to individual fixtures. Understanding the flow capacity, applications, and proper sizing for 1/2" pipe is essential for plumbers and contractors. This comprehensive guide covers everything you need to know about 1/2 inch pipe, including flow rates for different materials, common applications, and code requirements.
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Open CalculatorKey Specifications
Flow Capacity by Material
Copper (Type L)
0.545" ID, standard for water supply
PEX
0.485" ID, flexible installation
CPVC
0.485" ID, hot and cold water
PVC
0.485" ID, cold water only
1/2" Pipe Flow Capacity by Material
Maximum recommended flow rates (GPM) for 1/2" pipe at standard velocity (6 ft/s). Actual capacity varies with pressure, temperature, and pipe length.
| Material | Inside Diameter | C-Value | Max Flow @ 6 ft/s (GPM) | Typical Use |
|---|---|---|---|---|
| Copper (Type L) | 0.545" | 140 | 4.2 | Water supply, standard |
| PEX | 0.485" | 150 | 3.3 | Flexible installation |
| CPVC | 0.485" | 150 | 3.3 | Hot/cold water |
| PVC | 0.485" | 150 | 3.3 | Cold water only |
Common Uses
1/2" pipe is commonly used in the following applications:
- Branch lines to sinks and faucets
- Hot and cold water supply to fixtures
- Individual fixture connections
- Small residential water distribution
- Fixture supply lines
Applications
- Bathroom sink supply lines
- Kitchen sink supply lines
- Toilet supply lines
- Washing machine connections
- Dishwasher connections
- Ice maker lines
- Water filter connections
- Individual fixture branches
Frequently Asked Questions
What is the flow rate for 1/2 inch pipe?
Flow rate depends on material and pressure. For copper (0.545" ID) at 6 ft/s velocity: approximately 4.2 GPM. For PEX/CPVC (0.485" ID): approximately 3.3 GPM. Use our Pipe Sizing Calculator for exact flow rates based on your specific conditions.
Can 1/2 inch pipe supply a whole house?
No, 1/2" pipe is too small for main supply lines. It's designed for branch lines to individual fixtures. Main supply lines typically require 3/4" or 1" pipe depending on fixture count and flow requirements.
How many fixtures can 1/2 inch pipe supply?
1/2" pipe is typically used for single fixture connections or very small branch lines (1-2 fixtures). For multiple fixtures, use 3/4" or larger pipe. Use our Fixture Unit Load Calculator to determine proper sizing.
What is the inside diameter of 1/2 inch pipe?
Inside diameter varies by material: Copper Type L = 0.545", PEX/CPVC/PVC = 0.485". Always use actual inside diameter, not nominal size, for flow calculations.
Code Compliance
1/2" pipe is approved for branch lines to fixtures per IPC and UPC codes. Minimum size for fixture supply lines is typically 1/2". Always verify local code requirements as some jurisdictions may have specific restrictions.
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