Table
Conduit Trade Size to Metric Designator
Conduit Trade Size to Metric Designator reference with assumptions and boundary notes.
Reference boundary
Naming cross-reference only. It does not provide conduit fill, support spacing, bend limits, or product dimensions.
Reference table
Cross-reference common conduit trade sizes with metric designator labels.
| Trade size | Metric designator | Decimal trade size | Note |
|---|---|---|---|
| 1/2 in | 16 | 0.5 | Common small raceway label |
| 3/4 in | 21 | 0.75 | Trade label, not exact inside diameter |
| 1 in | 27 | 1 | Use product tables for dimensions |
| 1-1/4 in | 35 | 1.25 | Metric designator is a nominal label |
| 1-1/2 in | 41 | 1.5 | Confirm raceway type for dimensions |
| 2 in | 53 | 2 | Trade size cross-reference only |
| 3 in | 78 | 3 | Trade size cross-reference only |
| 4 in | 103 | 4 | Trade size cross-reference only |
Use notes
- Use this table for preliminary reference and arithmetic checks only.
- Confirm equipment ratings, product markings, installation conditions, utility requirements, and the local authority requirements before design or field use.