Electrical Voltage Drop Calculator

Voltage Drop Formula:

\[ V_d = \frac{2 \times I \times L \times R}{1000} \]

Voltage Drop (V_d):

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is an Electrical Voltage Drop Calculator?

Definition: This calculator estimates the voltage drop in an electrical circuit based on current, wire length, and wire resistance.

Purpose: It helps electricians and engineers ensure proper voltage levels in electrical installations by calculating potential voltage loss.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ V_d = \frac{2 \times I \times L \times R}{1000} \]

Where:

\( V_d \) — Voltage drop (volts)
\( I \) — Current (amperes)
\( L \) — Wire length (feet, one-way distance)
\( R \) — Wire resistance (ohms per 1000 feet)

Explanation: The formula accounts for both the outgoing and return paths (hence the factor of 2) in a typical circuit.

3. Importance of Voltage Drop Calculation

Details: Proper voltage drop calculation ensures electrical devices receive adequate voltage for optimal performance and prevents excessive power loss in wiring.

4. Using the Calculator

Tips: Enter the current in amperes, wire length in feet (one-way distance), and wire resistance in ohms per 1000 feet. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: Why is voltage drop important?
A: Excessive voltage drop can cause equipment malfunction, reduced efficiency, and potential safety hazards.

Q2: What's an acceptable voltage drop?
A: Typically 3% for branch circuits and 5% for feeder circuits, but check local electrical codes.

Q3: Where can I find wire resistance values?
A: Consult NEC tables or manufacturer specifications for specific wire types and sizes.

Q4: Does this work for DC circuits?
A: Yes, the same formula applies to both AC and DC circuits.

Q5: How can I reduce voltage drop?
A: Use shorter wire runs, larger wire gauges (lower resistance), or reduce the current load.