How many 10 gauge wires fit in 3/4 inch conduit?

A 3/4 inch EMT conduit holds up to 10 THHN wires of 10 AWG at 40% fill (NEC 2023, Chapter 9 Table 1). The same trade size holds 9 wires in PVC Schedule 40, 7 in PVC Schedule 80 and 10 in rigid metal conduit (RMC).

10 AWG THHN wires in 3/4 inch conduit by conduit type

10 AWG THHN wires in 3/4 inch conduit at 40% fill
Conduit	Inside area, in²	10 AWG THHN wires
Electrical metallic tubing (EMT)	0.533	10
Rigid PVC conduit, Schedule 40	0.508	9
Rigid PVC conduit, Schedule 80	0.409	7
Rigid metal conduit (RMC)	0.549	10

How the 40% conduit fill is calculated

Wires = inside area × 40% ÷ area of one wire. One 10 AWG THHN wire is 0.0211 in². In 3/4 inch EMT: 0.533 in² × 40% ÷ 0.0211 in² = 10.1, rounded down unless the decimal is 0.8 or more, so 10 wires.

What 10 AWG wires in 3/4 inch conduit usually carry

10 AWG wire feeds 30 amp loads such as dryers, water heaters and small air conditioners. Each 240 V circuit uses two hot conductors, and a ground wire counts toward the fill as well.

With more than three current-carrying conductors in one conduit, their ampacity must be reduced. The wire counts on this page are for THHN/THWN-2 insulation.

Related wire size, circuit and conduit answers

Sources

NFPA 70, National Electrical Code (2023): Percent of cross section of conduit and tubing for conductors, Chapter 9 Table 1
NFPA 70, National Electrical Code (2023): Dimensions and percent area of conduit and tubing, Chapter 9 Table 4
NFPA 70, National Electrical Code (2023): Dimensions of insulated conductors, Chapter 9 Table 5

Compared with 4 published documents, last on 2026-11-13

Carlon / Thomas & Betts (ABB) (catalog (edition not stated)): General information: wire fill based on Chapter 9 Table 1 — Conduit fill percentages
Florida International University (course notes, NEC edition not stated): Chapter III, Electrical Wiring Components (Figure 3.18, area of THHN conductors) — THHN areas for 14 to 6 AWG; the larger sizes match a training reproduction of the same table
Southwire Company, Power Cable Installation Guide (2005 (cites 2005 NEC)): Dimensions and percent area of conduit and tubing, Table 8 (EMT, rigid PVC Schedule 40 and 80) — Fill percentages and internal areas of EMT, PVC Schedule 40 and Schedule 80
Wheatland Tube (2022): Rigid Metal Conduit Submittal Sheet, weights and dimensions — Rigid metal conduit inside diameters; the areas follow from them

Calculated by Calculate.diy with the method of the National Electrical Code® (NEC®), 2023 edition; not the NEC text. Methodology. For planning only: check local code and use a licensed electrician.