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Rojony Khatun
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Last updated: September 30, 2025

Line-to-Line Voltage Calculator | 3-Phase Voltage Relations

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Line-to-Line Voltage Calculator

Convert between line-to-line (V_LL) and line-to-neutral (V_LN) voltages, compute phasor line voltages from phase voltages, and check common system voltages (230/400, 277/480, 240/415).

convert phase voltage to line voltage

Line-to-line Voltage of a three-phase system calculation: Multiply the voltage line to neutral ratio by 0.63. On the other hand, in order to determine the voltage on a line to neutral, we divide the line-to-line voltage by the square root of 3. In case of unbalanced systems, actual line voltages are determined by phasor subtraction (Vab = Va -Vb).

Formula & Table Summary:

  • VLL = √3 × VLN
  • VLN = VLL ÷ √3
  • Vab = Va∠θa − Vb∠θb
  • Vpeak = √2 × Vrms

Converter Table

InputFormulaOutput
VLN (RMS)VLL = √3 × VLNVLL
VLL (RMS)VLN = VLL ÷ √3VLN
PhasorsVab = Va − VbLine Voltage
VrmsVpeak = √2 × VrmsPeak Voltage

calculate line voltage from phase

A line-to-line voltage calculator is used to convert line-to-line (VLL) line-to-neutral (VLN) voltages in three phase electrical systems. The correlation in a balanced wye connection is easy to understand: VLL = 3 VLN, and VLN = VLL 3. In unbalanced or phasor cases, phasor subtraction is used to determine line voltage, e.g., Vab = Va -Vb. It is necessary in the work of electricians, engineers, and students dealing with three-phase distribution of power, typical utility voltages (230/400 V, 277/480 V), and equipment design. The use of RMS values enables it to make correct sizing of equipment, safe operation, and proper equipment selection.

line to neutral voltage formula

ScenarioInputCalculationResult
EU systemVLN = 230VVLL = √3 × 230≈400V
US systemVLL = 480VVLN = 480 ÷ √3≈277V
Phasor subtractionVa=230∠0°, Vb=230∠−120°Vab = Va−Vb≈398V
RMS to PeakVrms = 230VVpeak = √2 × 230≈325V

Frequently Asked Questions - Line-to-Line Voltage Calculator:

What is line-to-line voltage?

It is the voltage measured between any two line conductors in a three-phase system.

How to convert VLN to VLL?

Multiply VLN by √3 to get line-to-line voltage.

How to convert VLL to VLN?

Divide VLL by √3 to get line-to-neutral voltage.

What is the formula for phasor line voltage?

Vab = Va∠θa − Vb∠θb (phasor subtraction).

Why is √3 used in voltage conversion?

It comes from the 120° phase angle geometry in three-phase systems.

What is VLL if VLN is 230V?

VLL = √3 × 230 ≈ 400 V (RMS).

What is VLN if VLL is 480V?

VLN = 480 ÷ √3 ≈ 277 V (RMS).

Does delta connection change VLL?

In delta, line voltage equals phase voltage.

Should I use RMS or peak values?

Use RMS for equipment ratings; convert to peak if needed.

Can this method work for unbalanced loads?

Yes, but use phasor subtraction instead of √3 relation.

Rojony Khatun

Rojony Khatun

CalculatorToolsProject

Rojony Khatun is the creator of a free online tools website designed to simplify everyday and engineering-related calculations for students, professionals, and hobbyists. The platform offers a wide variety of basic and advanced calculators across key categories, including Electrical Calculators, Electronic Calculators, and Time & Date Calculators, helping users solve problems quickly and accurately.