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AWG to mm² Wire Gauge Calculator

10 AWG = 5.26 mm² (Diameter: 2.59 mm)

Typical copper wire current capacity: 35 Amps at 75°C.

Convert standard American Wire Gauge (AWG) sizes to metric cross-sectional area (mm²) and diameters. Check standard ampacity codes for electric cable ratings.

Interactive AWG to mm² Converter

Area (mm²) 5.26 mm²
Diameter (mm) 2.59 mm

AWG to mm² Ampacity Reference Table

AWG Size Area (mm²) Diameter (mm) NEC Ampacity (Amps at 75°C)
4/0 107.22 mm² 11.68 mm 230 A
3/0 85.01 mm² 10.4 mm 200 A
2/0 67.43 mm² 9.27 mm 175 A
1/0 53.49 mm² 8.25 mm 150 A
1 42.41 mm² 7.35 mm 130 A
2 33.62 mm² 6.54 mm 115 A
4 21.15 mm² 5.19 mm 85 A
6 13.3 mm² 4.11 mm 65 A
8 8.37 mm² 3.26 mm 50 A
10 5.26 mm² 2.59 mm 35 A
12 3.31 mm² 2.05 mm 25 A
14 2.08 mm² 1.63 mm 20 A

Understanding AWG Wire Gauge System

The American Wire Gauge (AWG) system uses a logarithmic scale where each decrease of 6 gauge numbers doubles the wire cross-sectional area. A lower AWG number means thicker wire with higher current capacity. For example, 6 AWG (13.30 mm²) is roughly double the area of 8 AWG (8.37 mm²).

Area Ratio: Each gauge step = ×1.26 area change
Diameter Ratio: Each gauge step = ×1.123 diameter change
6-gauge rule: Every 6 AWG steps = doubling of area

Ampacity and Wire Selection

Ampacity (ampere capacity) is the maximum current a wire can carry continuously without exceeding its temperature rating. NEC Table 310.16 lists ampacities for copper and aluminum conductors at 60°C, 75°C, and 90°C insulation ratings.

When selecting wire size, consider: circuit breaker rating, voltage drop (keep under 3% for branch circuits), conductor bundling derating, ambient temperature, and installation method (conduit, cable tray, or free air).

Frequently Asked Questions — AWG Wire Gauge

What is the formula to convert AWG to mm²?
The wire diameter in millimeters is d = 0.127 × 92^((36-AWG)/39). The cross-sectional area in mm² is calculated using the formula A = (π/4) × d². For AWG 0 and smaller (1/0, 2/0, 3/0, 4/0), use negative AWG values: 1/0 = 0, 2/0 = -1, 3/0 = -2, 4/0 = -3.
How many mm² is 10 AWG?
10 AWG is equal to approximately 5.26 mm² with a diameter of 2.59 mm. The NEC ampacity rating for 10 AWG copper wire at 75°C is 35 Amps, making it suitable for 20-amp household circuits with margin.
What AWG wire is used for household wiring?
Standard 15-amp household circuits use 14 AWG (2.08 mm²) copper wire. 20-amp circuits require 12 AWG (3.31 mm²). Major appliances like dryers and ranges use 10 AWG (5.26 mm²) or larger. Always follow local electrical codes for wire sizing.
What is the difference between AWG and metric wire sizes?
AWG (American Wire Gauge) uses a gauge number system where smaller numbers indicate larger wires. Metric wire is specified by cross-sectional area in mm². A lower AWG number = thicker wire = more current capacity. For example, 6 AWG (13.30 mm²) carries 65A vs 10 AWG (5.26 mm²) carrying 35A.
How does temperature affect wire ampacity?
Wire current capacity decreases as ambient temperature increases. NEC ampacity ratings are based on 30°C ambient. For every 1°C above 30°C, derate the ampacity by approximately 0.5-0.8% depending on wire size. Bundled cables in conduit generate more heat and require additional derating factors.

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