TradeHub Tools Field Reference Chart
EMT THHN Conduit Fill Chart
Source scope: NEC Chapter 9 raceway fill logic for identical copper THHN/THWN-2 conductors in EMT, aligned to Annex C Table C.1-style same-size EMT fill values. Field reference only; not an official NEC table replacement.
Page URL: https://www.tradehub.tools/resources/electrical/field-tables/emt-thhn-conduit-fill-chart
Primary Field Chart
EMT Conduit Fill Capacity Chart
This TradeHub field chart shows the maximum number of identical copper THHN/THWN-2 conductors in common EMT trade sizes using NEC Annex C Table C.1-style same-size EMT fill values. Counts of 1 or 2 are shown as lookup values; those conditions use the applicable one- or two-conductor fill basis rather than the three-or-more 40% fill basis.
| Conductor Size | 1/2 in EMT | 3/4 in EMT | 1 in EMT | 1-1/4 in EMT | 1-1/2 in EMT | 2 in EMT |
|---|---|---|---|---|---|---|
| 14 AWG | 12 | 22 | 35 | 61 | 84 | 138 |
| 12 AWG | 9 | 16 | 26 | 45 | 61 | 101 |
| 10 AWG | 5 | 10 | 16 | 28 | 38 | 63 |
| 8 AWG | 3 | 6 | 9 | 16 | 22 | 36 |
| 6 AWG | 2 | 4 | 7 | 12 | 16 | 26 |
| 4 AWG | 1 | 2 | 4 | 7 | 10 | 16 |
| 3 AWG | 1 | 1 | 3 | 6 | 8 | 13 |
| 2 AWG | 1 | 1 | 3 | 5 | 7 | 11 |
| 1 AWG | 1 | 1 | 1 | 4 | 5 | 8 |
| 1/0 AWG | 1 | 1 | 1 | 3 | 4 | 7 |
| 2/0 AWG | 1 | 1 | 1 | 3 | 3 | 6 |
| 3/0 AWG | 1 | 1 | 1 | 2 | 3 | 5 |
| 4/0 AWG | 1 | 1 | 1 | 1 | 2 | 4 |
Chart basis: identical copper THHN/THWN-2 conductors in EMT, aligned to NEC Annex C Table C.1-style same-size EMT fill values. Counts of 1 or 2 are shown as lookup values; those conditions use the applicable one- or two-conductor fill basis rather than the three-or-more 40% fill basis.
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Calculator-use note: use the Conduit Fill Calculator when conductor sizes are mixed, grounding conductors are included, the raceway is not EMT, compact aluminum is selected, the raceway is a qualifying nipple, or jam-ratio/pull-condition review matters.
TradeHub Tools field reference only. Verify against the adopted NEC cycle, conductor markings, manufacturer data, site conditions, and local inspection authority.
Scope Boundary
When This Chart Applies
- Use for EMT only: This chart is not a PVC, IMC, RMC, flexible raceway, or cable sleeve reference.
- Use for identical conductors only: The chart assumes all conductors in the raceway are the same THHN/THWN-2 size and insulation type.
- Use for baseline fill capacity: The chart gives a fast same-size lookup. It does not check ampacity derating, ambient correction, terminal limits, voltage drop, or box fill.
- Check 1- and 2-conductor cases carefully: Counts of 1 or 2 are shown as lookup values, but those conditions use the applicable one- or two-conductor fill basis rather than the three-or-more 40% fill basis.
Calculator Handoff
When to Use the Conduit Fill Calculator
This chart stops being enough when the raceway set is not a simple same-size EMT pull. Mixed conductor sizes, bare equipment grounding conductors, compact aluminum, PVC Schedule 40, PVC Schedule 80, IMC, RMC, qualifying nipples, parallel raceways, and jam-ratio concerns require the actual cross-sectional area calculation.
Related Code References
Source Scope
Source Alignment and Use Scope
This TradeHub field reference chart is based on NEC Chapter 9 raceway fill logic for a narrow same-size EMT condition. It is provided for screening and planning only and does not reproduce the full NEC table set or replace the adopted code, conductor markings, product data, site conditions, or local inspection authority. Review the TradeHub Code Citation & Source Log for source alignment records and the TradeHub Methodology page for how field references are scoped.
FAQ
EMT THHN Conduit Fill FAQ
Can this EMT conduit fill chart be used for mixed wire sizes?
No. This chart is limited to identical THHN or THWN-2 conductors in EMT. Mixed conductor sizes, grounding conductors, compact aluminum, and different raceway types require an area-based conduit fill calculation.
Do grounding conductors count for conduit fill?
Yes. Equipment grounding conductors occupy physical raceway space and count for conduit fill. Use the Conduit Fill Calculator when grounding conductors are part of the raceway set.
Is conduit fill the same as ampacity derating?
No. Conduit fill checks physical raceway area. Ampacity derating checks current-carrying conductor count, ambient temperature, insulation rating, and terminal limits separately.