d = 0.127 * 92^((36 - n) / 39)
A = (π / 4) * d²
dn = √(4A / π)
n = -39 * log₉₂(dn / 0.127) + 36
Where：
d = Diameter (mm)
A = Cross sectional area (m m²)
n = Gauge number (awg)
π = 3.1415926535
Convert between AWG, mm², kcmil, millimeters, and inches for electrical wiring. Ideal for cable selection, power system design, electrical installations, and engineering. Supports real-time bidirectional conversion with high precision.
| Unit | Full Name | Description |
|---|---|---|
| AWG | American Wire Gauge | A logarithmic standardized system; higher numbers indicate thinner wires. Widely used in North America. |
| mm² | Square millimeters | International unit for cross-sectional area of wire. |
| kcmil / MCM | Kilo-circular mil | 1 kcmil = 1000 circular mils; used for large cables like transformer leads. |
| mm | Millimeter | Diameter in millimeters, useful for measurement. |
| in | Inch | Diameter in inches, primarily used in North America. |
AWG → Diameter (mm):
dmm = 0.127 × 92^((36 - AWG)/39)
AWG → Area (mm²):
A = π/4 × dmm²
kcmil → mm²:
mm² = kcmil × 0.5067
mm → in:
in = mm / 25.4
in → mm:
mm = in × 25.4
Diameter ≈ 2.053 mm
Area = π/4 × (2.053)² ≈ 3.31 mm²
Approximate AWG: 10 AWG
(Actual diameter: ~2.588 mm)
500 × 0.5067 ≈ 253.35 mm²
5 ÷ 25.4 ≈ 0.1969 in
AWG 4 has a cross-sectional area of ~21.16 mm².
Convert to kcmil: 21.16 ÷ 0.5067 ≈ 417.4 kcmil
Wire and cable selection and procurement — choosing the right gauge for current load
Electrical installation and wiring design — ensuring compliance with NEC or IEC standards
Power system capacity calculation — determining conductor size for transformers and feeders
Industrial equipment wiring standards — matching motor leads, control circuits, and busbars
Electrical exams and teaching — helping students understand wire sizing and current ratings
DIY electronics and PCB design — selecting appropriate jumper wires and traces
ANSI/ICEA S-73-532: Standard for Wire and Cable
NEC (National Electrical Code) – Article 310: Conductors for General Wiring
IEC 60228: Conductors of insulated cables
UL 44: Rubber Insulated Wires and Cables
Textbooks: "Electrical Engineering Principles and Applications" by Allan R. Hambley, "Handbook of Electric Power Calculation" by A. E. Fitzgerald
The largest standard AWG is AWG 40, which is very thin (~0.081 mm diameter).Smaller gauges (lower numbers) go up to AWG 0000 (4/0), which is about 11.68 mm in diameter.
Yes! Use the inverse of the AWG formula:
First, find the diameter in mm.
Then solve for AWG using:
AWG = 36 - 39 × log₂(dmm / 0.127)
Or use this calculator for instant results.
Yes!
- mm² is the metric unit of cross-sectional area.
- kcmil is an imperial-based unit used in North America.
Conversion: 1 kcmil = 0.5067 mm²
So, 1000 kcmil ≈ 506.7 mm².
kcmil (kilo-circular mil) is used in North America for large conductors like transformer leads and underground cables.It's based on circular mils (area of a circle with 1 mil diameter), so 1 kcmil = 1000 circular mils.This system simplifies calculations for round wires.
Use the formula:
dmm = 0.127 × 92^((36 - AWG)/39)
Then calculate area: A = π/4 × dmm²
Alternatively, use a lookup table or this calculator for accuracy.
AWG stands for American Wire Gauge. It's a logarithmic scale where higher numbers mean thinner wires.
For example: AWG 18 is thinner than AWG 14.
Each step down (e.g., from 14 to 12) doubles the cross-sectional area.
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