Enter the phase voltage into the calculator to determine the line-to-line voltage.

Line to Line Voltage Calculator

Voltage Only
Voltage & 3φ Power

Enter any 1 value to calculate the missing variable.

Line to Line Voltage Formula

The following equation is used to calculate the Line to Line Voltage.

VL-L = SQRT(3) * PV
  • Where VL-L is the line-to-line voltage
  • PV is the phase voltage

To calculate the line-to-line voltage, multiply the phase voltage by the square root of 3.

This formula is for 3-phase systems that are equally separated by 120 degrees.

Phase to Line-to-Line Voltage Conversion Table (3-Phase, RMS)
Phase Voltage (V) Line-to-Line Voltage (V)
1220.785
2441.569
4883.138
60103.923
90155.885
100173.205
110190.526
115199.186
120207.846
127219.970
200346.410
220381.051
230398.372
240415.692
254439.941
277479.778
346599.290
347601.022
398689.356
500866.025
* Rounded to 3 decimals. Three-phase relation (RMS): V_LL = √3 × V_Ph ≈ 1.732 × V_Ph.

What is Line to Line Voltage?

Definition:

Line to line voltage and Phase to Phase voltage are two different kinds of voltage that are found in AC circuits. In a three phase circuit, the voltage can be split in three different parts and each of these parts is called line to line voltage.

Line to line voltage is defined as the difference between two lines where the phases cross each other at right angles. Voltage is measured in volts. In a three phase system there are three lines and therefore 3 line to line voltages.

The line-to-line voltage is the voltage measured between any two phases of a 3-phase, 4 wire system. The Line to Line voltage for a 3 phase, 4 wire system is equal to the sum of all 3 wires times the phase sequence plus Neutral.