How Many 1/0 AWG Wires Fit in EMT Conduit?

Complete NEC-compliant fill chart for 1/0 AWG THHN wires in Electrical Metallic Tubing (EMT) conduit. Maximum wire counts for all standard conduit sizes.

Quick Answer

For 1/0 AWG THHN wires in EMT conduit at 40% fill (3+ wires):

  • • 3/4" EMT: 1 wires
  • • 1" EMT: 1 wires
  • • 1-1/4" EMT: 3 wires

1/0 AWG in EMT Conduit Fill Chart

Conduit Size Max Wires (40% Fill) Fill % Max Wires (Nipple 60%) Fill %
3/4" 1 35% 1 35%
1" 1 21% 2 43%
1-1/4" 3 37% 4 50%
1-1/2" 4 36% 6 55%
2" 7 39% 10 55%
2-1/2" 12 38% 18 57%
3" 19 40% 28 59%
3-1/2" 24 39% 37 59%
4" 31 39% 47 59%

Understanding the Fill Chart

According to NEC (National Electrical Code) Chapter 9, Table 1, the maximum conduit fill percentage depends on the number of conductors:

  • 1 conductor: 53% fill maximum
  • 2 conductors: 31% fill maximum
  • 3 or more conductors: 40% fill maximum
  • Nipples (24" or less): 60% fill maximum

This chart shows the maximum number of 1/0 AWG THHN conductors that can fit in each EMT conduit size while maintaining NEC compliance.

Calculation Example

Question: How many 1/0 AWG THHN wires can fit in 1" EMT conduit?

Wire area: 0.1855 sq in per conductor

Conduit internal area: 0.864 sq in

Allowable fill (40%): 0.3456 sq in

Maximum wires: 0.3456 ÷ 0.1855 = 1 wires

Answer: You can fit up to 1 wires of 1/0 AWG THHN in 1" EMT conduit.

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