Electrical Conduit Size Chart & Types: Complete Guide for Safe Wiring

1.What is the Electrical Conduit?

What is the conduit? In short, it’s a type of protective tubing used to route and protect electrical wiring in buildings, machinery, and outdoor installations. An electrical conduit helps protect wires from physical damage, moisture, corrosion, and other environmental hazards.

This also organizes wiring systems and should make upgrading or repairing easier later on.

There are a variety of electrical conduit types, each designed to protect wiring in the ideal environment. Which kind of conduit is appropriate depends on your location, exposure, and convenience of installation.

Types of Electrical Conduit

There are several electrical conduit types, each suited to different environments and wiring needs:

• Rigid Metal Conduit (RMC): This is a strong and very stiff metal electrical conduit favorable for outdoor and industrial installations.
• Electrical Metallic Tubing (EMT): EMT is a lightweight metal electrical conduit that’s very common in commercial settings because of its ease of installation.
• Flexible Metal Conduit (FMC): FMC is typically used around motors and machines and offers flexibility for tight and curved spaces.
• Electrical conduits PVC:Best suited for underground or wet locations, this non metallic PVC option is corrosion resistant. Also, due to its lightweight and easy to cut nature, it has grown popular among residential users.
• Liquid-tight Flexible Conduit (LFMC): Perfect for harsh or wet environments, as this is designed to repel moisture, oil, and chemicals.

 

2. What is the Electrical Conduit Size Chart?

An electric conduit size chart is a quick reference tool that lists standard electrical conduit pipe sizes and wire fill capacities. It’s a must-have for electricians, contractors, and DIYers looking to ensure their wiring inside conduit pipes is safe and efficient. Understanding what an electrical conduit is goes beyond just knowing its purpose—it includes knowing how to size it correctly.

Trade Size	Nominal Internal Diameter		Total Area 100%		60%		1 Wire 53%		2 Wires 31%		Over 2 Wires 40%
	mm	in.	mm²	in.²	mm²	in.2	mm²	in.?	mm²	in.2	mm²	in.²
%	15.3	0.602	184	0.285	110	0.171	98	0.151	57	0.088	74	0.114
%	20.4	0.804	327	0.508	196	0.305	173	0.269	101	0.157	131	0.203
1	26.1	1.029	535	0.832	321	0.499	284	0.441	166	0.258	214	0.333
1%	34.5	1.360	935	1.453	561	0.872	496	0.770	290	0.450	374	0.581
1%	40.4	1.590	1282	1.986	769	1.192	679	1.053	397	0.616	513	0.794
2	52.0	2.047	2124	3.291	1274	1.975	1126	1.744	658	1.020	850	1.316
2Y	62.1	2.445	3029	4.695	1817	2.817	1605	2.488	939	1.455	1212	1.878
3	77.3	3.042	4693	7.268	2816	4.361	2487	3.852	1455	2.253	1877	2.907
3%	89.4	3.521	6277	9.737	3766	5.842	3327	5.161	1946	3.018	2511	3.895
4	101.5	3.998	8091	12.554	4855	7.532	4288	6.654	2508	3.892	3236	5.022
5	127.4	5.016	12748	19.761	7649	11.857	6756	10.473	3952	6.126	5099	7.904
6	153.2	6.031	18433	28.567	11060	17.140	9769	15.141	5714	8.856	7373	11.427

Using the wrong size causes overheating, difficulty pulling wires, or code violations. This chart helps determine the sizes of electrical conduit pipes that can contain different amounts of wires and their gauges. Whether you're installing a single circuit or running several cables, the chart helps you choose the right size.

 

3. What Materials are Used for Electrical Conduit?

Different installation environments and requirements determine the material used to make each electrical conduit. Here are the most common materials used:

• Galvanized Steel: A thick, strong, and heavy-duty metal that is used for rigid metal conduit (RMC) and is ideal for any outdoor and industrial scenarios.
• Aluminum: Lighter than steel, aluminum is also corrosion-resistant, making it suitable in areas with moisture exposure.
• Stainless steel: Provides excellent corrosion resistance, suitable for harsh or chemical environments.

• PVC (Polyvinyl Chloride): Electrical conduit PVC is a quick and simple-to-work material that is excellent for underground and wet applications.

• HDPE (High-Density Polyethylene): HDPE conduit is flexible and durable and is commonly used for telecommunications and buried electrical lines.
• Fiberglass: Non-conductive and corrosion-resistant, fiberglass conduit is well-suited to high-temperature or corrosive environments.
• Nylon and Other Plastics: Used in flexible conduit types where flexibility and chemical resistance are needed.

Professionals can select the right material according to safety, durability, and code compliance.

 

4. What is the Application of the Electrical Conduit?

Conduit is used in electrical installations to protect, organize, and route wiring systems. From houses to industrial plants, conduits are chosen depending on factors like safety, exposure, and the complexity of wiring. Here are the most common uses for electrical conduit.

Residential Wiring

In residential environments, electrical conduit is used to enclose and protect wiring systems inside walls, ceilings, attics, and basements. It protects against pests, moisture, and inadvertent punctures during home improvements. Conduit also makes it easier to replace or upgrade wires later without tearing down walls.

Commercial Buildings

Conduit is also essential in commercial buildings such as offices, shopping centers, and schools to safely manage lighting, outlets, internet, and HVAC systems. Conduit shields the wires from damage and maintains a clean infrastructure. It also contributes to meeting strict building and safety standards.

Industrial Environments

Conduit protects the wiring from heat, vibration, chemicals, and mechanical impact in industrial environments. Rigid metal electrical conduit is commonly utilized because of its strength and resistance. Such environments require robust and safe wiring solutions for substantial equipment and processes.

Outdoor Installations

For outdoor applications, electrical conduit is common for covering exposed wires from weather, UV, and physical damage. Electrical conduit PVC is standard for landscape lighting, outdoor outlets, and security systems. It protects wires against the elements, whether rain or scorching heat.

Underground Wiring

Conduits protect cables from the effects of soil pressure, moisture, and corrosion experienced in underground electrical systems. It is also quite common with residential and commercial buildings for power lines to be connected to detached structures or lighting systems. It protects the wiring and prolongs the life of the electrical system.

 

5. How to Choose the Right Electrical Conduit?

Selecting the appropriate electrical conduit is critical to ensuring safety and adherence to electrical standards. It relies on things like the installation environment, the type of wiring, and assurance needs. Here’s what to keep in mind when choosing the best conduit for your project:

Assess the Environment

Identify where the conduit will be installed – indoor, outdoor, underground, or industrial. For wet or corrosive environments, electrical conduit made of PVC or stainless steel is appropriate. RMC or EMT is suitable for areas susceptible to physical damage.

Understand the Wiring Needs

Pay attention to how many and what size wires will be run. Use an electrical conduit size chart to see if the maximum wire fill is within code limits for your conduit.

Choose the Right Material

Select the material based on durability, flexibility, and cost. Metal conduits offer high impact resistance, while plastic ones are lightweight and corrosion-resistant.

Check Local Electrical Codes

Always consult local building codes or a licensed electrician to ensure your conduit type and size meet safety and compliance standards for your location.

Location

For commercial indoor or exposed areas, the EMT or RMC conduits would work best. They are durable and comply with building codes.

Flexibility Needs

Use Flexible Metal Conduit (FMC) if your installation area has tight turns or equipment movement. It flexes readily and accommodates movement. It is ideal for machinery or arrangements that need periodic movement or adjustment.

Corrosion Resistance

In outdoor or corrosive environments, use aluminum or coated conduits. These materials are strong against rusting and chemicals. They’re perfect for coastal regions, industrial factories, or where wires are exposed to extreme environments.

Wire Capacity

To prevent overcrowding, please refer to a conduit size chart for your wire. It means the conduit needs to be able to have wires fit inside without putting them under stress. Additionally, proper sizing facilitates smoother wire-pulling practices for installation and future upgrades.

Code Requirements

Local electrical code regulations always apply. The codes dictate what type and size of conduit you can use in various applications. Compliance helps ensure safety, legality, and passing inspections.

Durability

Use steel or IMC conduits in high-traffic or impact risk areas. They are strong and durable. They protect wiring in warehouses, garages, and industrial settings where durability matters.