Conduit Fill Chart for EMT and PVC
These charts show the maximum number of same-size THHN/THWN-2 conductors allowed in each trade size of conduit. They are computed from NEC Chapter 9: Table 1 (fill percentage), Table 4 (conduit internal area) and Table 5 (conductor area), and they apply Note 7, which lets you round up by one conductor when the calculation ends in 0.8 or more. The counts match the Annex C tables.
For a mix of wire sizes, use the conduit fill calculator.
EMT conduit fill chart (THHN/THWN-2)
| THHN/THWN-2 | 1/2" | 3/4" | 1" | 1-1/4" | 1-1/2" | 2" |
|---|---|---|---|---|---|---|
| 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 | 1 | 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 | 0 | 1 | 1 | 3 | 4 | 7 |
| 2/0 AWG | 0 | 1 | 1 | 2 | 3 | 6 |
| 3/0 AWG | 0 | 1 | 1 | 1 | 3 | 5 |
| 4/0 AWG | 0 | 0 | 1 | 1 | 1 | 4 |
PVC Schedule 40 conduit fill chart (THHN/THWN-2)
| THHN/THWN-2 | 1/2" | 3/4" | 1" | 1-1/4" | 1-1/2" | 2" |
|---|---|---|---|---|---|---|
| 14 AWG | 11 | 21 | 34 | 60 | 82 | 135 |
| 12 AWG | 8 | 15 | 25 | 43 | 59 | 99 |
| 10 AWG | 5 | 9 | 15 | 27 | 37 | 62 |
| 8 AWG | 3 | 5 | 9 | 16 | 21 | 36 |
| 6 AWG | 1 | 4 | 6 | 11 | 15 | 26 |
| 4 AWG | 1 | 1 | 4 | 7 | 9 | 16 |
| 3 AWG | 1 | 1 | 3 | 6 | 8 | 13 |
| 2 AWG | 1 | 1 | 3 | 5 | 7 | 11 |
| 1 AWG | 0 | 1 | 1 | 3 | 5 | 8 |
| 1/0 AWG | 0 | 1 | 1 | 3 | 4 | 7 |
| 2/0 AWG | 0 | 1 | 1 | 2 | 3 | 6 |
| 3/0 AWG | 0 | 1 | 1 | 1 | 3 | 5 |
| 4/0 AWG | 0 | 0 | 1 | 1 | 1 | 4 |
PVC Schedule 80 has thicker walls and a smaller internal area than Schedule 40 of the same trade size, so it holds fewer conductors. Use the calculator and select Schedule 80.
How to read the chart
Find the conductor size in the left column and read across to the trade size. The number is the maximum count of that conductor, including equipment grounding conductors, that may be installed in that raceway.
Example: four 10 AWG THHN (two hots, a neutral and a ground) fit in ½" EMT, which allows up to 5.
Fill percentages behind the chart
| Conductors in the raceway | Maximum percent fill |
|---|---|
| 1 | 53% |
| 2 | 31% |
| More than 2 | 40% |
| Nipple 24 in or shorter | 60% |
Because two conductors are limited to 31%, the count for large conductors in small conduit can drop sharply. For example, a single 6 AWG THHN fits in ½" PVC Schedule 40, but two do not.
"What size conduit for…" quick answers
Smallest trade size at 40% fill for common copper THHN/THWN-2 circuits and feeders, with an equipment grounding conductor from Table 250.122:
| Circuit | Conductors | Total area | EMT | PVC Sch. 40 |
|---|---|---|---|---|
| 30 A, 240 V | 3 × 10 AWG (2 hots + ground) | 0.0633 in² | ½" | ½" |
| 50 A range, 120/240 V | 3 × 8 AWG + 1 × 10 AWG | 0.1309 in² | ¾" | ¾" |
| 60 A subpanel, or 6/3 equivalent | 3 × 6 AWG + 1 × 10 AWG | 0.1732 in² | ¾" | ¾" |
| 100 A subpanel | 3 × 3 AWG + 1 × 8 AWG | 0.3285 in² | 1" | 1" |
| 125 A subpanel | 3 × 1 AWG + 1 × 6 AWG | 0.5193 in² | 1-¼" | 1-¼" |
| 150 A subpanel | 3 × 1/0 + 1 × 6 AWG | 0.6072 in² | 1-½" | 1-½" |
| 200 A subpanel | 3 × 3/0 + 1 × 6 AWG | 0.8544 in² | 2" | 2" |
A few of these are tight. The 100 A feeder uses 0.3285 of the 0.3456 in² allowed in 1" EMT, and the 200 A feeder misses 1-½" EMT (0.8144 in²), so it goes to 2" EMT (1.3424 in²). Wire-size pages such as 100 amp subpanel show the same checks in context.
- Four 12 AWG plus a 12 AWG ground: 5 × 0.0133 = 0.0665 in², which fits in ½" EMT.
- Aluminum feeders: XHHW-2 aluminum has its own areas in Chapter 9 Table 5. Use those, not the THHN values in this chart.
Worked example: mixed home run in EMT
A home run carries two 120 V, 20 A circuits with their own neutrals (four 12 AWG), one 240 V, 20 A circuit (two 12 AWG) and one 240 V, 30 A circuit (two 10 AWG). One 10 AWG equipment ground, sized for the largest breaker, serves all of them (250.122(C)).
- Total area: 6 × 0.0133 + 3 × 0.0211 = 0.1431 in².
- ½" EMT: 40% is 0.1216 in². Over by 0.0215 in². Doesn't fit.
- ¾" EMT: 40% is 0.2132 in². Fits, with room for five more 12 AWG conductors.
- Ampacity: the raceway has eight current-carrying conductors (the ground doesn't count), so every circuit needs the adjustment factor from Table 310.15(C)(1). THHN may start from its 90°C value; check that each conductor still covers its breaker.
For mixes like this, the conduit fill calculator does the arithmetic.
Cable assemblies like NM-B in conduit are treated differently (Chapter 9, Note 9). A cable counts as a single conductor at its overall area, and a flat cable is treated as round using its larger dimension.
Beyond the fill limit
- More than three current-carrying conductors in one raceway require ampacity adjustment (80% for 4–6, 70% for 7–9 and 50% for 10–20, per Table 310.15(C)(1)). Neutrals that carry only unbalanced current and equipment grounds don't count.
- Limit bends to 360° total between pull points.
- Leave room for future circuits in home runs and underground conduits, where adding a pipe later is expensive.
Common mistakes
- Leaving out the equipment ground or the neutral from the fill count. Every conductor counts.
- Using Note 7 rounding on a mix of sizes. It applies only to a calculation of same-size conductors.
- Forgetting the 31% limit for two conductors, which catches large feeders in small conduit.
- Reading an EMT count for PVC. Schedule 40 and Schedule 80 PVC have smaller internal areas than EMT of the same trade size.
- Counting NM-B cable as separate conductors. A cable is one conductor at its overall area.
Conduit fill in estimating
Fill decides the pipe size, and pipe size drives material and labor on every run. On a takeoff, conduit size is usually picked per home run or feeder from a chart like this one, then adjusted when circuits are combined. SparkQuote's takeoff software reads PDF plans and counts devices for you.
Frequently asked questions
How many 12 gauge wires fit in 1/2 inch EMT?
Nine 12 AWG THHN conductors.
How many 10 gauge wires fit in 3/4 PVC?
Nine 10 AWG THHN in ¾" PVC Schedule 40, and ten in ¾" EMT.
How many wires can go in a 1 inch conduit?
In 1" EMT: 35 of 14 AWG, 26 of 12 AWG, 16 of 10 AWG, 9 of 8 AWG or 7 of 6 AWG (THHN).
What size conduit for 6/3 wire?
For three 6 AWG THHN plus a 10 AWG ground, ¾" EMT or PVC Schedule 40. For 6/3 NM-B or UF cable pulled through a sleeve or conduit, the cable counts as one conductor at its overall area, using its larger dimension (Note 9), and one conductor may fill 53%. Measure the cable or take the manufacturer's dimension, then compare.
Does the neutral count in conduit fill?
Yes. Every conductor counts toward fill, including neutrals and grounds.
Related
Computed from NEC 2023 Chapter 9 Tables 1, 4 and 5, Note 7. Last updated: October 6, 2026. Check results against the code edition and local amendments your jurisdiction enforces and with the AHJ; electrical work should be done by qualified people.