ElectraKit

Conduit Dimensions: EMT, IMC, RMC and PVC

Compare trade sizes, outside diameters, and published inside dimensions for EMT, IMC, RMC, and Schedule 40 and 80 PVC electrical conduit.

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Read the dimensions

Trade size is a name, not the measured bore or outside diameter. Compare the same dimension and the same basis when identifying raceway, checking a product submittal, or selecting a compatible fitting.

The steel tables below use Wheatland product data. The PVC tables use CANTEX published minimum inside diameters. These are deliberately distinguished from typical dimensions and from the values used in NEC fill tables. Millimeters are conversions of the displayed inch dimensions.

EMT dimensions

Wheatland nominal OD; ID is informational, not a UL-797 requirement.

EMT: common trade sizes, 1/2 through 4
Trade sizeOD (in.)Nominal / informational ID (in.)OD (mm)Corresponding ID (mm)
1/20.7060.62217.9315.80
3/40.9220.82423.4220.93
11.1631.04929.5426.64
1-1/41.5101.38038.3535.05
1-1/21.7401.61044.2040.89
22.1972.06755.8052.50
2-1/22.8752.73173.0269.37
33.5003.35688.9085.24
3-1/24.0003.834101.6097.38
44.5004.334114.30110.08

IMC dimensions

Wheatland nominal OD; nominal ID is calculated from nominal OD and wall thickness.

IMC: common trade sizes, 1/2 through 4
Trade sizeOD (in.)Nominal / informational ID (in.)OD (mm)Corresponding ID (mm)
1/20.8150.66020.7016.76
3/41.0290.86426.1421.95
11.2901.10532.7728.07
1-1/41.6381.44841.6136.78
1-1/21.8831.68347.8342.75
22.3602.15059.9454.61
2-1/22.8572.55772.5764.95
33.4763.17688.2980.67
3-1/23.9713.671100.8693.24
44.4664.166113.44105.82

RMC dimensions

Wheatland nominal OD and nominal ID; applicable manufacturing tolerances remain separate.

RMC: common trade sizes, 1/2 through 4
Trade sizeOD (in.)Nominal / informational ID (in.)OD (mm)Corresponding ID (mm)
1/20.8400.63221.3416.05
3/41.0500.83626.6721.23
11.3151.06333.4027.00
1-1/41.6601.39442.1635.41
1-1/21.9001.62448.2641.25
22.3752.08360.3252.91
2-1/22.8752.48973.0263.22
33.5003.09088.9078.49
3-1/24.0003.570101.6090.68
44.5004.050114.30102.87

PVC Schedule 40 dimensions

CANTEX drawing dated July 13, 2010: nominal OD and minimum ID, not a typical ID.

PVC Schedule 40: common trade sizes, 1/2 through 4
Trade sizeOD (in.)Minimum ID (in.)OD (mm)Corresponding ID (mm)
1/20.8400.57821.3414.68
3/41.0500.78026.6719.81
11.3151.00433.4025.50
1-1/41.6601.33542.1633.91
1-1/21.9001.56448.2639.73
22.3752.02160.3251.33
2-1/22.8752.41473.0261.32
33.5003.00888.9076.40
3-1/24.0003.486101.6088.54
44.5003.961114.30100.61

PVC Schedule 80 dimensions

CANTEX drawing dated May 22, 2017: nominal OD and minimum ID, not a typical ID.

PVC Schedule 80: common trade sizes, 1/2 through 4
Trade sizeOD (in.)Minimum ID (in.)OD (mm)Corresponding ID (mm)
1/20.8400.50221.3412.75
3/41.0500.69826.6717.73
11.3150.91033.4023.11
1-1/41.6601.22742.1631.17
1-1/21.9001.44648.2636.73
22.3751.88160.3247.78
2-1/22.8752.25073.0257.15
33.5002.82088.9071.63
3-1/24.0003.280101.6083.31
44.5003.737114.3094.92

Use the correct dimension

  • Use OD to compare the physical tube size, but use the fitting’s listing and named trade size to establish compatibility.
  • Use the applicable code fill table and the actual conductor construction for a raceway fill check. Do not substitute a manufacturer minimum ID for a code-table area without verifying the method.
  • Confirm the product, material, coating, tolerance, and fitting system. Aluminum, flexible raceway, and other products are outside these tables.
  • Check the current manufacturer submittal for larger trade sizes and dimensional tolerances. Product dimensions do not establish permitted uses or installation compliance.

Download the conduit dimension tables (CSV)

All 50 displayed rows, including the nominal/informational/minimum basis for each family. Contains no conduit-fill results.

For a fill check use the existing conduit fill calculator. For field layout see the bending multiplier guide.

Sources

Browse all reference tables, guides, and templates