Voltage Drop Calculator

Maintaining Potential: The Voltage Drop Calculator

In an ideal electrical circuit, the voltage supplied by the source would be the same at every point. In reality, all wires have some amount of electrical resistance. As current flows through a wire, some of the electrical potential (voltage) is 'lost' or 'dropped' across the length of the wire due to this resistance. This phenomenon is known as voltage drop. For long wire runs or high-current applications, this voltage drop can be significant. If the voltage drops too much, a device at the end of the wire may not receive enough voltage to operate correctly. For example, a 12V light at the end of a long wire might only receive 10V and will therefore be dimmer than expected.

Calculating the expected voltage drop is a critical step for electricians and electrical engineers when designing safe and efficient circuits. It ensures that the correct gauge (thickness) of wire is chosen for a specific load and distance to keep the voltage drop within acceptable limits (typically 3-5%). This simple calculator uses Ohm's Law (V=IR) to find the voltage drop across a wire, given the current flowing through it and the wire's total resistance.

The Voltage Drop Formula (Ohm's Law)

The voltage drop (Vd) across a conductor can be calculated using Ohm's Law if you know the current and the resistance.

Voltage Drop (V) = Current (I) × Resistance (R)

To perform a full voltage drop calculation for a specific wire run, you would first need to determine the wire's total resistance using its material properties, length, and gauge.