Wire Size Calculator — Calculate Electrical Wire Gauge & Capacity

Wire Size Calculator

Calculate the correct wire gauge for your electrical projects. Understand how current, voltage, distance, and installation type affect wire size selection and safety.

Step 1: Electrical Parameters

Understanding Current Requirements

The current (amps) is the most critical factor in wire sizing. Higher currents require thicker wires to prevent overheating and voltage drop. Always check your device specifications for current requirements.

Step 2: Installation Details

3%

About Voltage Drop

Voltage drop is the reduction in voltage as electricity travels through a wire. Excessive voltage drop can cause equipment to malfunction. For most applications, a voltage drop of 3% or less is recommended.

Wire Size Results

Summary
Wire Gauge Comparison
Ampacity Analysis

Recommended Wire Size

12 AWG
Voltage Drop: 2.4V (2.0%)
Maximum Current
25 Amps
Voltage Drop
2.4V (2.0%)
Wire Diameter
2.05 mm
Cross-Section Area
3.31 mm²

Wire Gauge Comparison

Wire Gauge (AWG) Diameter (mm) Cross-Section (mm²) Max Current* Resistance (Ω/1000ft)

*Maximum current for copper wire in free air at 30°C

Ampacity Analysis

Wire Sizing Formula

Wire Size = f(Current, Distance, Voltage, Material, Installation)

Wire size is determined by calculating the minimum gauge that can handle the required current without excessive voltage drop or overheating, considering material resistivity, installation type, and insulation temperature rating.

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