WireSizing.com is a free wire gauge reference and sizing tool. All wire specifications on this site are calculated from published standards and formulas — no data is copied from other sources.
Our calculations are based on the following standards and references:
AWG Dimensions: ASTM B258 — Standard Specification for Standard Nominal Diameters and Cross-Sectional Areas of AWG Sizes of Solid Round Wires Used as Electrical Conductors
Ampacity: NEC (NFPA 70) Table 310.16 — Allowable Ampacities of Insulated Conductors
Metric Sizes: IEC 60228 — Conductors of Insulated Cables
Resistivity: ASM International Metals Reference Book, CRC Handbook of Chemistry and Physics
Wire Properties: Calculated from first principles using material resistivity, density, and geometric formulas
AWG Diameter: d(n) = 0.005 × 92(36−n)/39 inches
Cross-sectional Area: A = π/4 × d²
Resistance: R = ρ × L / A (where ρ = resistivity)
Voltage Drop: Vdrop = 2 × I × R × L (single phase)
Weight: W = A × ρmaterial × L
Skin Depth: δ = √(ρ / (π × f × μ0))
This site is for informational and reference purposes only. It is not a substitute for professional electrical engineering advice. Always consult a licensed electrician and follow local building codes and the National Electrical Code (NEC) for actual electrical installations.
Ampacity values shown are based on specific conditions (30°C ambient, not more than 3 current-carrying conductors in raceway). Actual ampacity may be lower due to ambient temperature, conduit fill, bundling, and other derating factors per NEC 310.15.
Questions, corrections, or suggestions? Email us at [email protected].