Wire Gauge Calculator

What Is an AWG Wire Gauge Calculator?

American Wire Gauge (AWG) is the standard sizing system for solid round conductive wire in North America. Our AWG Wire Gauge Calculator converts a gauge number into conductor diameter, cross-sectional area, and copper resistance per kilometer at 20°C. That makes it useful for choosing wire sizes, checking voltage drop, and estimating heating limits.

How the Calculation Works

$$d_n = 0.127 \times 92^{(36-n)/39}$$

$$A = \pi \left(\frac{d}{2}\right)^2$$

$$R = \frac{\rho L}{A}$$

Where:

• n is the AWG number, with 1/0 = 0, 2/0 = -1, 3/0 = -2, and 4/0 = -3
• d is the conductor diameter in millimeters
• A is the cross-sectional area in square millimeters
• ρ is the resistivity of copper, 1.68 × 10⁻⁸ Ω·m
• L is the conductor length

Worked Example

For 14 AWG, the diameter is d = 0.127 × 92^((36 - 14)/39) = 1.628 mm. The area is then A = π × (1.628 / 2)² = 2.08 mm², and the copper resistance works out to roughly 8.1 Ω per kilometer.

Related tools include the Wire Resistance Calculator, the Wheatstone Bridge Calculator, and the Work and Power Calculator.