Voltage Drop Calculator

Our Voltage Drop Calculator is a powerful tool designed to help electricians, engineers, and DIY enthusiasts calculate voltage drop in electrical circuits. Voltage drop occurs when current flows through wire, causing resistance and resulting in a reduction of voltage at the load end of the circuit.

Why Calculate Voltage Drop?

Calculating voltage drop is crucial for proper electrical system design. Excessive voltage drop can lead to poor performance of electrical equipment, overheating, and energy waste. The National Electrical Code (NEC) recommends limiting voltage drop to 3% for branch circuits and 5% for combined feeder and branch circuits.

Key Features:

• Calculate voltage drop for both copper and aluminum conductors
• Support for single-phase and three-phase systems
• Multiple wire sizes from 14 AWG to 4/0 AWG
• Length input in either feet or meters
• Support for common system voltages (120V, 240V, etc.)
• Clear indication if voltage drop exceeds recommended limits

How to Use the Calculator:

• Current: Enter the load current in amperes (A).
• Wire Length: Enter the one-way distance from the power source to the load. The calculator will account for the return path.
• Wire Material: Select either copper or aluminum conductor material.
• Wire Size: Choose the appropriate wire gauge (AWG).
• System Voltage: Select the nominal system voltage.
• Circuit Type: Specify whether the circuit is single-phase or three-phase.

Understanding the Results:

• Voltage Drop (V): The absolute voltage reduction in volts.
• Percentage Drop (%): The voltage drop expressed as a percentage of the system voltage.
• Status: Indicates whether the voltage drop is within acceptable limits (less than 3%) or exceeds recommendations.

Common Applications:

• Residential Wiring: Ensuring proper voltage for household appliances and fixtures
• Commercial Installations: Planning electrical systems for offices and retail spaces
• Industrial Systems: Designing power distribution for machinery and equipment
• Renewable Energy: Calculating wire sizing for solar panel installations
• Outdoor Lighting: Planning for long runs of landscape lighting or security systems

Wire Size Selection:

When designing electrical circuits, it's important to consider both ampacity (current-carrying capacity) and voltage drop. While a wire may be rated to safely carry a certain amount of current based on its ampacity, it might still cause excessive voltage drop over long distances. This calculator helps you determine if your selected wire size will maintain adequate voltage at the load end.

Remember that while this calculator provides valuable information for planning electrical installations, all electrical work should comply with local codes and regulations and should be performed or inspected by qualified professionals.