Wire Ampacity Chart
A wire size and amp chart: the allowable ampacity of copper and aluminum conductors from 14 AWG to 500 kcmil, in the 60, 75 and 90 °C columns of NEC 2026 Table 310.16.
Updated
For reference only. Always verify with the NEC edition adopted by your AHJ.
Ampacity by wire size
| Size | Copper (A) | Aluminum / copper-clad Al (A) | ||||
|---|---|---|---|---|---|---|
| 60 °C | 75 °C | 90 °C | 60 °C | 75 °C | 90 °C | |
| #14 AWG | 15 | 20 | 25 | — | — | — |
| #12 AWG | 20 | 25 | 30 | 15 | 20 | 25 |
| #10 AWG | 30 | 35 | 40 | 25 | 30 | 35 |
| #8 AWG | 40 | 50 | 55 | 35 | 40 | 45 |
| #6 AWG | 55 | 65 | 75 | 40 | 50 | 55 |
| #4 AWG | 70 | 85 | 95 | 55 | 65 | 75 |
| #3 AWG | 85 | 100 | 115 | 65 | 75 | 85 |
| #2 AWG | 95 | 115 | 130 | 75 | 90 | 100 |
| #1 AWG | 110 | 130 | 145 | 85 | 100 | 115 |
| 1/0 AWG | 125 | 150 | 170 | 100 | 120 | 135 |
| 2/0 AWG | 145 | 175 | 195 | 115 | 135 | 150 |
| 3/0 AWG | 165 | 200 | 225 | 130 | 155 | 175 |
| 4/0 AWG | 195 | 230 | 260 | 150 | 180 | 205 |
| 250 kcmil | 215 | 255 | 290 | 170 | 205 | 230 |
| 300 kcmil | 240 | 285 | 320 | 195 | 230 | 260 |
| 350 kcmil | 260 | 310 | 350 | 210 | 250 | 280 |
| 400 kcmil | 280 | 335 | 380 | 225 | 270 | 305 |
| 500 kcmil | 320 | 380 | 430 | 260 | 310 | 350 |
Values in amperes at 30 °C ambient with no more than 3 current-carrying conductors. — means the table lists no value (14 AWG aluminum).
Which column applies
Terminations decide first (110.14(C)). A conductor may be rated 90 °C, but the circuit cannot use more ampacity than the lowest-rated termination allows. Under 110.14(C)(1): (a) circuits rated 100 A or less, or marked for14-1 AWG conductors, use the 60 °C column, unless the equipment is listed and marked for 75 °C; (b) circuits over 100 A, or marked for conductors larger than 1 AWG, use the 75 °C column. Our calculator defaults to the more conservative column and lets you switch when your equipment is marked for 75 °C. The 90 °C column is the starting value for ambient correction and conductor-count adjustment when the insulation is rated 90 °C, but the final ampacity still cannot exceed the termination rating.
Small conductors have a breaker cap (240.4(D)). Overcurrent protection is limited to 30 A for 10 AWG copper, 20 A for 12 AWG copper, 15 A for 14 AWG copper, 25 A for 10 AWG aluminum, 15 A for 12 AWG aluminum, even where the column shows more.
Conditions change the number (310.15). A hotter ambient applies a correction under 310.15(B)(1), and more than 3 current-carrying conductors applies an adjustment under 310.15(C)(1). Corrections start from the column of the insulation rating, and the corrected value is still held to the termination column.
Voltage drop is not included; long runs may need a larger conductor.
Ampacity chart questions
- Which column of the ampacity chart do I use?
- Use the column of the lowest temperature rating among the conductor insulation and the terminations (110.14(C)). Circuits of 100 A or less, and 14-1 AWG conductors, default to the 60 °C column unless the equipment is marked for 75 °C. The 90 °C column is the starting value for ambient correction and conductor-count adjustment when the insulation is rated 90 °C, but the final ampacity cannot exceed the temperature rating of the terminations (110.14(C)).
- Why is 14 AWG aluminum blank?
- Table 310.16 lists no ampacity for 14 AWG aluminum, so it is shown as a dash here.
- Do these ampacities already include corrections?
- No. They assume a 30 °C ambient and no more than 3 current-carrying conductors. Apply 310.15(B)(1) for other ambient temperatures and 310.15(C)(1) for more conductors.
- Is ampacity the same as the breaker size?
- 240.4(D) limits overcurrent protection to 30 A for 10 AWG copper, 20 A for 12 AWG copper, 15 A for 14 AWG copper, 25 A for 10 AWG aluminum, 15 A for 12 AWG aluminum, whatever the chart shows.
Quick answers by circuit size: 20 amp, 50 amp, 200 amp service.
You can read the NEC 2026 for free at NFPA free access. Need a size for a specific load? Use the wire size calculator.