Mr Calcu | Wire Gauge Calculator: Size, Ampacity & Voltage Drop

Calculate wire gauge, ampacity, and voltage drop for electrical projects. Supports AWG, SWG, and metric systems.

Wire Gauge Calculator Description

Understanding Wire Gauge Standards

Wire gauge determines the thickness and current-carrying capacity of electrical wires. The American Wire Gauge (AWG) system is the most common in North America, while the Standard Wire Gauge (SWG) is used in the UK. Thicker wires (lower AWG numbers) handle higher currents with less resistance, reducing voltage drop over long distances. According to Wikipedia, AWG standards date back to 1857 and are critical for electrical safety.

Why Wire Size Matters

Choosing the wrong wire gauge can lead to overheating, energy loss, or fire hazards. The National Fire Protection Association (NFPA) emphasizes proper wire sizing in the National Electrical Code (NEC). For example, a 10 AWG copper wire can safely carry 30 amps in most residential applications, while a 14 AWG wire is limited to 15 amps. Always consult local codes before wiring.

Calculating Voltage Drop

Voltage drop occurs when current travels through a wire, causing power loss. Longer runs or higher currents exacerbate this issue. The formula for voltage drop is V_drop = I × R, where I is current and R is resistance per foot (found in wire specifications). The U.S. Department of Energy recommends keeping voltage drop below 3% for optimal efficiency.