July 21, 2022 2 min read

The Actual Inside & Outside Diameters of Common EMT Conduit Sizes

 If you go to your local hardware or home store and look in the electrical aisle, you'll find EMT Conduit in a wide range of sizes and lengths. You may be surprised to learn that the listed size on the sticker doesn't actually refer to the inside or outside diameter. That is known as the trade size. In this blog we will briefly describe the trade size and then get the actual diameters of three common EMT Conduit sizes.

What Does The EMT Conduit Trade Size Mean?

EMT Conduit Trade Size Sticker

Trade sizes can mean different things depending on the application. For example, PVC trade sizes refer to the inner diameter of the pipe whereas trade sizes of copper pipes refer to the outside diameter. This can be confusing especially if you're mainly looking to complete a desk or other DIY project and not actually running water or gas through your home.
Electricians use EMT Conduit to house cables and wires throughout industrial and commercial buildings. The trade size of EMT refers to the maximum bundle size that can fit in the pipe. For example, 1/2" EMT Conduit has an actual inner diameter of .622". The 1/2" measurement is letting you know that it's not recommended to run a bundle of wires larger than .50" through the conduit.

What You Need To Know For Building

Man Assembling Black Pipe Connector

For us DIYers and pipe builders, the trade size doesn't really matter unless you plan to run wires through the pipes in your project. What you really want to know is the inside and outside diameters of the conduit you're using. Knowing these measurements can help you find new accessories and solve specific challenges that may come up while you're working on your build.

What Are The Diameters Of 1/2" EMT Conduit?

The outside diameter of 1/2" EMT Conduit is .706" and the inside diameter is .622".

What Are The Diameters Of 3/4" EMT Conduit?

The outside diameter of 3/4" EMT Conduit is .922" and the inside diameter is .824".

What Are The Diameters Of 1" EMT Conduit?

The outside diameter of 1" EMT Conduit is 1.163" and the inside diameter is 1.049".


Currently these are the three sizes of EMT Conduit that work with the maker Pipe Connectors. If you need the measurements of other EMT sizes check out this link here. Remember to keep an eye out for the trade size for the actual diameters when looking at all pipes and not just conduit. If you have any questions please don't hesitate to contact us. Thanks for reading and happy building.


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