TOOLS
Convert AWG wire gauge to conductor diameter in mm and cross-section in mm², or enter a diameter or area and find the nearest standard AWG and IEC 60228 metric size. Includes kcmil and circular mils.
Conductor Diameter
0.8118 mm
0.03196 in
Values are for a bare solid conductor per ASTM B258. Stranded wire of the same AWG has a slightly larger overall diameter.
Equivalent AWG
17 AWG
Exact equivalent of the combined cross section
Wires Needed
—
Combining wires matches conductor cross section (current capacity), not the overall bundle diameter. Paralleled wires share current evenly only when their gauge, length, and terminations match, and bundled conductors also derate thermally.
Imperial Length
1 3/16 in
0.03 m
Tape measure fractions are rounded to your selected precision, from 1/8 down to 1/64 inch, and always reduced to the simplest form.
This calculator provides engineering guidance only. AWG values describe bare solid conductors, so verify stranded constructions and critical dimensions against the manufacturer datasheet.
quick guide
Enter any one value (gauge, diameter, or cross-section) and the other two update instantly.
1. Pick an AWG gauge from 0000 (4/0) to 50 — diameter and cross-section appear immediately.
2. Or type a diameter (mm or inch) or an area (mm², kcmil, cmil) to convert in the other direction.
3. Read the results: diameter in mm and inches, cross-section in mm² and circular mils, the nearest standard AWG, and the nearest IEC 60228 metric size.
4. Paste values straight from a datasheet — “14 AWG”, “2.5 mm”, “0.75 mm²” or “1,022 cmil” are recognized and routed to the right field automatically.
AWG follows the exact ASTM B258 formula: diameter (mm) = 0.127 × 92(36 − AWG) / 39. For a common hook-up wire size like 20 AWG:
20 AWG = 0.812 mm = 0.518 mm²
The cross-section follows from the diameter: area = π/4 × d² ≈ 0.518 mm², which is about 1,020 circular mils. The nearest IEC 60228 metric size is 0.5 mm².
American Wire Gauge (AWG) is the standard sizing system for round solid conductors in North America, defined in ASTM B258. Sizes run in a geometric progression: a smaller gauge number means a larger wire, every 6 gauge steps double the diameter, and every 10 steps multiply the cross-section by ten. Above 0 AWG the sizes continue as 00 (2/0), 000 (3/0), and 0000 (4/0), the largest standard size. European designs usually specify conductors by cross-section in mm² per IEC 60228 instead — which is why converting between the two systems is such a common step in cable design.
The values describe a bare solid conductor. Stranded wire of the same AWG has the same total copper cross-section but a slightly larger overall diameter — check the manufacturer datasheet for the finished OD.
Need to combine several wires into one equivalent size? Use the Combined Wire Gauge Calculator. Converting metric drawings to tape-measure fractions? Try the mm to Inches Fraction Calculator, or browse all our engineering tools.
