Wire gauge calculator

Wire Gauge Size Chart

American wire gauge (AWG) size calculator and chart.

* @ 68°F or 20°C

** Diameter and the cross-sectional area do not include the insulation.

*** Results may change with real wires: different resistivity of material and number of strands in the wire

AWG chart

Wire gauge calculations

Wire diameter calculations

The n gauge wire diameter d_n in inches (in) is equal to 0.005in times 92 raised to the power of 36 minus gauge number n, divided by 39:

d_{n (in)} = 0.005 in × 92^(36-n)/39

The n gauge wire diameter d_n in millimeters (mm) is equal to 0.127mm times 92 raised to the power of 36 minus gauge number n, divided by 39:

d_{n (mm)} = 0.127 mm × 92^(36-n)/39

Wire cross-sectional area calculations

The n gauge wire's cross-sectional area A_n in kilo-circular mils (kcal) is equal to 1000 times the square wire diameter d in inches (in):

A_{n (kcal)} = 1000×d_n² = 0.025 in² × 92^(36-n)/19.5

The n gauge wire's cross sectional area A_n in square inches (in²) is equal to pi divided by 4 times the square wire diameter d in inches (in):

A_{n (in}2₎ = (π/4)×d_n² = 0.000019635 in² × 92^(36-n)/19.5

The n gauge wire's cross sectional area A_n in square millimeters (mm²) is equal to pi divided by 4 times the square wire diameter d in millimeters (mm):

A_{n (mm}2₎ = (π/4)×d_n² = 0.012668 mm² × 92^(36-n)/19.5

Wire resistance calculations

The n gauge wire resistance R in ohms per kilofeet (Ω/kft) is equal to 0.3048×1000000000 times the wire's resistivity ρ in ohm-meters (Ω·m) divided by 25.4² times the cross-sectional area A_n in square inches (in²):

R_{n (Ω/kft)} = 0.3048 × 10⁹ × ρ_(Ω·m) / (25.4² × A_{n (in}2₎)

The n gauge wire resistance R in ohms per kilometer (Ω/km) is equal to 1000000000 times the wire's resistivity ρ in ohm-meters (Ω·m) divided by the cross-sectional area A_n in square millimeters (mm²):

R_{n (Ω/km)} = 10⁹ × ρ_(Ω·m) / A_{n (mm}2₎