How the conversion works
AWG is a logarithmic scale defined by ASTM B258: the conductor area in mm² is 0.012668 × 92^((36 − gauge) ÷ 19.5). That is the exact formula this converter uses — no lookup-table rounding. Because both systems use standard discrete sizes, the practical question is rarely "what is the exact equivalent" but "which size do I actually buy" — and the safe answer is always the next standard size with equal or larger area, which the converter shows alongside the exact value.
What the conversion does not cover
Equal copper area means equal conductivity, but not equal paperwork: ampacity ratings differ between the North American NEC tables and IEC installation rules, and depend on insulation temperature class, bundling and ambient conditions. Use this converter to translate sizes, then verify current ratings against the applicable standard — and for sizing a DC run from scratch, start with the Cable Voltage Drop calculator instead.
Methodology
The converter UI, the pairs table and the displayed formula all call the same conversion function, and the substitute recommendations round upward only.
- AWG area formula and gauge definition — ASTM B258 standard for wire gauge sizes
- Metric standard cross-sections (1.5–95 mm²) — IEC 60228 conductor classes
- Ampacity must be checked separately per installation — NEC ampacity tables (North America) and IEC installation rules
Assumptions last reviewed on 27 August 2026. If a source disagrees with your battery or equipment datasheet, trust the datasheet.
Frequently asked questions
Why do bigger wires have smaller AWG numbers?
The gauge number historically counts wire-drawing passes — more passes produce thinner wire. Sizes thicker than 1 AWG continue as 1/0, 2/0, 3/0 and 4/0.
Is a metric cable with the same area a safe substitute for an AWG size?
For conductivity yes — equal or larger copper area conducts equally or better, which is why the converter recommends the next standard size up. Ampacity ratings still depend on insulation and installation rules, so check those separately.
What are the useful rules of thumb?
Every 3 gauge steps roughly doubles the area, every 10 steps multiplies it by ten. 10 AWG ≈ 5.3 mm² is a handy anchor point.