EMT Conduit Sizes Chart
Quick answer: EMT conduit trade size is not the same as actual outside diameter. For example, 1/2-inch EMT has an outside diameter of about 0.706 inch and an inside diameter of about 0.622 inch. Use trade size for fittings, but use actual dimensions and code fill tables when planning wire pulls.
EMT Conduit Sizes Table
| Trade size | Outside diameter | Inside diameter | Approx. internal area | Common note |
|---|---|---|---|---|
| 1/2 in | 0.706 in | 0.622 in | 0.304 sq in | Small branch circuits and short runs |
| 3/4 in | 0.922 in | 0.824 in | 0.533 sq in | More practical when several conductors are pulled |
| 1 in | 1.163 in | 1.049 in | 0.864 sq in | Common larger branch/feed runs |
| 1-1/4 in | 1.510 in | 1.380 in | 1.496 sq in | Useful for larger wire pulls |
| 1-1/2 in | 1.740 in | 1.610 in | 2.036 sq in | Large feeders and easier pulls |
| 2 in | 2.197 in | 2.067 in | 3.356 sq in | Large conduit runs |
| 2-1/2 in | 2.875 in | 2.731 in | 5.858 sq in | Commercial/large service work |
| 3 in | 3.500 in | 3.356 in | 8.846 sq in | Large commercial runs |
| 3-1/2 in | 4.000 in | 3.834 in | 11.545 sq in | Large commercial runs |
| 4 in | 4.500 in | 4.334 in | 14.753 sq in | Large commercial/service applications |
EMT vs IMC vs Rigid Outside Diameter
EMT, IMC, and rigid metal conduit share trade-size names, but the actual dimensions and wall construction are not identical. Fittings must match the conduit type, not just the trade size printed in a chart.
| Trade size | EMT OD | IMC OD | Rigid OD | Fitment warning |
|---|---|---|---|---|
| 1/2 in | 0.706 in | 0.815 in | 0.840 in | Do not mix EMT fittings with rigid fittings |
| 3/4 in | 0.922 in | 1.029 in | 1.050 in | Similar trade name, different OD |
| 1 in | 1.163 in | 1.290 in | 1.315 in | Use the correct connector family |
| 1-1/4 in | 1.510 in | 1.638 in | 1.660 in | Measure if adapting old work |
| 1-1/2 in | 1.740 in | 1.883 in | 1.900 in | Trade size alone is not enough |
| 2 in | 2.197 in | 2.360 in | 2.375 in | Check conduit type before buying straps |
How To Use EMT Size Data
- Use trade size when buying EMT, connectors, straps, and boxes.
- Use outside diameter when checking clamps, holes, brackets, or pass-throughs.
- Use inside diameter and code fill tables when planning conductor pulls.
- Do not use this chart as a substitute for electrical code, permit, or inspection requirements.
Source Notes
EMT dimensions were checked against published EMT dimension references including Taylor Walraven’s EMT data, NEC-style conduit table references, and conduit sizing calculators. Always use the electrical code and local inspection requirements for actual wiring work.
