4/0 (0000)
Diameter
- mm
- in
Area
- mm²
- kcmil
Resistance
- Ω/km
- Ω/kft
Allowable Ampacity (NEC Standard)
| 60°C (140°F) | 75°C (167°F) | 90°C (194°F) |
|---|---|---|
| - | - | - |
AWG Calculator
Look up wire gauge diameter, area, resistance, and standard ampacity values.
⚠️ Engineering Caution:
This tool is intended for screening and pre-check workflows. Results are usually directionally useful, but they
can still shift with equipment selection, environmental conditions, naming conventions, revision status, or
interpretation rules. Confirm any value that affects ordering, substitution, compliance, or installation before
acting on it.
Frequently Asked Questions
What does an AWG calculator tell you?
An AWG calculator helps you look up wire gauge diameter, cross-sectional area, resistance, and related ampacity reference values for common conductor sizes.
Does a smaller AWG number mean a larger wire?
Yes. In the American Wire Gauge system, smaller gauge numbers represent larger conductor diameters, and larger gauge numbers represent smaller wires.
Understanding American Wire Gauge (AWG) Standards
The American Wire Gauge (AWG) system is a standardized wire gauge system used predominantly in North America to denote the cross-sectional area of round, solid, non-ferrous electrically conducting wire. The AWG system assigns a numerical designation inversely proportional to the physical diameter of the conductor—smaller numbers represent thicker wires, while larger numbers denote thinner wires.
The Mathematics Behind AWG
The diameter of an AWG wire is determined by the formula: d(n) = 0.005 × 92^((36−n)/39) inches, where n is the AWG number. This geometric progression means that each 6-gauge decrease approximately doubles the wire diameter, and each 3-gauge decrease approximately doubles the cross-sectional area.
NEC Ampacity Standards
The National Electrical Code (NEC) Table 310.16 provides the allowable ampacities for insulated conductors rated up to and including 2000 Volts, 60°C through 90°C. These values assume not more than three current-carrying conductors in a raceway, cable, or earth, with an ambient temperature of 30°C (86°F). Higher temperature ratings allow greater ampacity, but the overcurrent protection for 14 AWG (15A), 12 AWG (20A), and 10 AWG (30A) is limited by NEC Section 240.4(D).