Voltage Drop Calculator



Wire Gauge (AWG)

Wire Length (feet)

If the calculated voltage drop is greater than 0.75 for 12V or 1.5 for 24V, we recommend increasing wire gauge or reducing wire length.

How to Use the Voltage Drop Calculator

Enter the numeric value of total watts used in your installation. This is the measurement of the total power consumed by your LED lighting system, not the watt rating of your power supply. Please refer to the power requirement chart to estimate the watts you are using. Tip: Watts is calculated by multiplying volts by amps used in your LED system: Watts = Volts x Amps

Enter either 12 or 24, depending on the voltage of your LED lights. Tip: Do not include "V" or "Volts" in this field, enter numeric values only.

Wire Gauge (AWG)
Enter the gauge (thickness) of the wire you are using in your LED tape lighting system. Tip: The smaller the number, the thicker the wire. Common gauges for LED light installations: 18, 20, 22

Wire Length
Enter the length (in feet) of power feed wire between your power supply output and the front of the first LED strip in your lighting system.

Understanding Voltage Drop

Voltage drop is a natural occurrence in low-voltage lighting systems. It is the gradual decrease in voltage that occurs along the length of power feed wires to the LED lights, and varies depending on the type and size of the LED tape light installation. It is a function of wire length, wire thickness and the energy or total watts used by the LED lights.

Voltage drop only becomes undesirable if you notice the brightness in one area of your LED lighting is objectionably different than in another area. LED light color and brightness are best when power feed wires from the power supply to the LED strip, or array of strips, is delivering as close to the 12V or 24V voltage of the LED tape light as possible. With longer lengths of LED tape lighting, voltage drop also occurs along the tape light. As a practical approach, test your lighting prior to final installation.

If voltage drop appears to be a concern, shorten your power feed wires or switch to a heavier gauge wire (lower AWG number), or shorten the length of your LED tape lighting. You can also consider using an additional 24 volt or 12 volt power supply to create a second, separate installation. Armacost Lighting has a wide assortment of LED Strip Light Wire and LED Power Supplies.

In Summary

Excessive voltage drop = reduced brightness and color accuracy

Longer LED tape = an increase in voltage drop

Shorter or thicker wires = higher brightness and color consistency

Calculate Voltage Drop for Optimal LED Light Performance