Cable Sizing Tool

Voltage Drop Calculator

Calculate voltage drop for cable runs based on length, wire gauge, and current. Essential for power distribution design.

Voltage Drop Calculator

Calculate voltage drop for your cable run

Best Practices

Voltage Drop Guidelines

Recommended voltage drop limits for different applications.

≤ 3%

Recommended

Ideal for sensitive electronics, lighting, and motor applications. Minimizes energy waste and ensures reliable operation.

3-5%

Acceptable

Acceptable for general-purpose loads. NEC maximum for branch circuits. May cause dimming in lights or reduced motor torque.

> 5%

Excessive

Too high for most applications. Can cause equipment malfunction, overheating, and significant energy loss.

Understanding Voltage Drop

Voltage drop occurs due to the resistance of conductors. As current flows through wire, some energy is lost as heat. The formula is: V = I × R × L where I is current, R is resistance per unit length, and L is the round-trip cable length.

Solutions for high voltage drop: Use larger wire gauge, reduce cable length, increase system voltage, or split the load across multiple circuits.

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