NEC Table 310.16 Ampacity Chart
A printable NEC 310.16 ampacity chart in PDF: copper and aluminium, 60 / 75 / 90 °C insulation, every AWG and kcmil from 14 AWG to 2 000 kcmil. Reviewed by a licensed PE.
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Single A4 page, ~ 80 kB, Cu + Al across all three temperature columns.
Download PDF (full chart)Need to size a specific circuit including voltage drop and breaker selection? Use the wire size calculator.
The chart — preview
Full Cu/Al × 60/75/90 °C reproduced here for reference. The downloadable PDF includes the same data plus derating notes.
| Size | mm² | Cu 60 °C | Cu 75 °C | Cu 90 °C | Al 60 °C | Al 75 °C | Al 90 °C |
|---|---|---|---|---|---|---|---|
| 14 AWG | 2.08 | 15 | 20 | 25 | — | — | — |
| 12 AWG | 3.31 | 20 | 25 | 30 | 15 | 20 | 25 |
| 10 AWG | 5.26 | 30 | 35 | 40 | 25 | 30 | 35 |
| 8 AWG | 8.37 | 40 | 50 | 55 | 35 | 40 | 45 |
| 6 AWG | 13.3 | 55 | 65 | 75 | 40 | 50 | 55 |
| 4 AWG | 21.2 | 70 | 85 | 95 | 55 | 65 | 75 |
| 3 AWG | 26.7 | 85 | 100 | 115 | 65 | 75 | 85 |
| 2 AWG | 33.6 | 95 | 115 | 130 | 75 | 90 | 100 |
| 1 AWG | 42.4 | 110 | 130 | 145 | 85 | 100 | 115 |
| 1/0 AWG | 53.5 | 125 | 150 | 170 | 100 | 120 | 135 |
| 2/0 AWG | 67.4 | 145 | 175 | 195 | 115 | 135 | 150 |
| 3/0 AWG | 85.0 | 165 | 200 | 225 | 130 | 155 | 175 |
| 4/0 AWG | 107.2 | 195 | 230 | 260 | 150 | 180 | 205 |
| 250 kcmil | 127 | 215 | 255 | 290 | 170 | 205 | 230 |
| 350 kcmil | 177 | 260 | 310 | 350 | 210 | 250 | 280 |
| 500 kcmil | 253 | 320 | 380 | 430 | 260 | 310 | 350 |
Values for ≤ 2 000 V conductors, ≤ 3 CCC, 30 °C ambient. Derate per NEC 310.15(B)(1) and (B)(3)(a) for other conditions.
Quick examples
Example 1 — 100 A panel feeder, copper, 75 °C terminations. Read 75 °C Cu column: 3 AWG = 100 A. Compliant.
Example 2 — 60 A subpanel feed, aluminium, 75 °C terminations. Al 75 °C: 6 AWG = 50 A (insufficient); 4 AWG Al = 65 A works.
Example 3 — 200 A residential service, Cu, dwelling allowance. NEC 310.12 allows 2/0 AWG Cu for 120/240 V dwelling 200 A service. Strict 310.16 = 3/0 (200 A at 75 °C); the 310.12 allowance is the dwelling shortcut.
Example 4 — derating in a 50 °C attic. 8 AWG Cu 75 °C = 50 A base × 0.75 (310.15(B)(1) for 50 °C) = 37.5 A — must size up to 6 AWG (65 × 0.75 = 48.7 A) for a 40 A breaker.
- What is NEC Table 310.16?
- NEC Table 310.16 is the foundational ampacity table in the NFPA 70 / National Electrical Code. It lists the allowable current (ampacity) for insulated conductors rated 0–2 000 V, installed in raceway, cable, or earth, at 30 °C ambient with no more than three current-carrying conductors. Columns are split by temperature rating of the insulation (60 °C, 75 °C, 90 °C) and by conductor material (copper or aluminium / copper-clad aluminium).
- Which column do I use — 60 °C, 75 °C, or 90 °C?
- Use the lowest temperature rating of any device terminating the conductor. Per NEC 110.14(C): equipment rated ≤ 100 A or marked for use with #14–#1 AWG conductors uses the 60 °C column unless terminations are marked otherwise. Equipment rated > 100 A or marked for #1/0 AWG and larger uses the 75 °C column. The 90 °C column is used only for derating and adjustment; you cannot exceed the lower-rated termination value.
- How do I apply temperature correction?
- Multiply the base ampacity by the NEC Table 310.15(B)(1) correction factor for the actual ambient. Example: 4 AWG copper at 75 °C = 85 A base. In a 40 °C attic, factor = 0.88 → 85 × 0.88 = 74.8 A allowable. If more than three conductors are bundled, also apply the 310.15(B)(3)(a) adjustment: 4–6 conductors = 0.80, 7–9 conductors = 0.70, 10–20 conductors = 0.50.
- What is the small conductor rule?
- NEC 240.4(D) caps the breaker / fuse size on small copper and aluminium conductors regardless of what 310.16 lists: Cu 14 / 12 / 10 AWG → 15 / 20 / 30 A max breaker; Al 12 / 10 AWG → 15 / 25 A max breaker. So even if the 90 °C column shows 25 A for #14 Cu, you cannot install a 25 A breaker on it — only 15 A.
- Is this chart current with the 2023 NEC?
- Yes. The values reproduced and downloadable here match the NFPA 70 — 2023 Edition Table 310.16. The 2023 cycle made minor renumbering changes (formerly 310.15(B)(16) in NEC 2017) but ampacity values themselves have not changed for typical sizes since NEC 2014. Always verify against your local adopted edition before stamping a design.
Sources
- NFPA. NFPA 70 — National Electrical Code (2023). Article 310.16 — ampacities of insulated conductors; Article 310.15(B)(1)/(B)(3)(a) — derating; Article 240.4(D) — small-conductor rule; Article 110.14(C) — termination temperature.
- Mike Holt Enterprises. Understanding the National Electrical Code, Vol. 1. Chapter 3 commentary on 310.16 application.
- NEMA. NEMA WC 70 / ICEA S-95-658 — Power Cables Rated 2 000 Volts or Less. Manufacturer test basis for the ampacity values.