Calculator Form
Use this tool to convert line-to-line voltage to line-to-neutral voltage, reverse the value, or compare both entered values.
Example Data Table
| System | Line-to-Line Voltage | Formula | Line-to-Neutral Voltage | Use Case |
|---|---|---|---|---|
| Three Phase Wye | 400 V | 400 ÷ √3 | 230.94 V | General distribution panel |
| Three Phase Wye | 415 V | 415 ÷ √3 | 239.60 V | Industrial supply check |
| Three Phase Wye | 480 V | 480 ÷ √3 | 277.13 V | Lighting and commercial loads |
| Split Phase | 240 V | 240 ÷ 2 | 120 V | Residential branch circuits |
| Single Phase Two Wire | 230 V | 230 ÷ 1 | 230 V | Simple single phase supply |
Formula Used
The main formula depends on the selected electrical system. The calculator applies the ratio between line voltage and neutral voltage.
- Three phase wye:
VLN = VLL ÷ √3 - Reverse three phase wye:
VLL = VLN × √3 - Split phase:
VLN = VLL ÷ 2 - Single phase two wire:
VLN = VLL - Custom system:
VLN = VLL ÷ custom ratio - Three phase apparent power:
S = √3 × VLL × I - Real power:
P = S × power factor - Estimated impedance:
Z = VLN ÷ I - Neutral current:
IN = √(IA² + IB² + IC² - IAIB - IBIC - ICIA)
How to Use This Calculator
- Select the calculation mode.
- Choose the electrical system type.
- Enter line-to-line voltage or line-to-neutral voltage.
- Add current and power factor for load power estimates.
- Enter phase currents if you want neutral current.
- Press the calculate button.
- Review the result table above the form.
- Use CSV or PDF buttons to save the result.
Line to Neutral Voltage Guide
What Line to Neutral Means
Line to neutral voltage is the voltage measured between one live conductor and the neutral point. It is common in panels, outlets, lighting circuits, and control systems. The value is not always the same as line to line voltage. The difference depends on the supply system. In a balanced three phase wye system, the neutral point sits at the electrical center of the three phases. Because the phase angles are separated by 120 degrees, the voltage from one line to neutral is lower than the voltage between two lines.
Why the Ratio Matters
The most used relation is simple. Divide line to line voltage by the square root of three. This gives the line to neutral value for a balanced wye supply. A 400 volt three phase supply gives about 230.94 volts to neutral. A 480 volt supply gives about 277.13 volts to neutral. These numbers help when selecting breakers, lamps, controls, meters, and connected equipment. A wrong assumption can lead to poor sizing. It may also damage sensitive devices.
More Than Basic Conversion
This calculator adds more options than a simple converter. You can work forward from line to line voltage. You can also reverse the calculation from line to neutral voltage. A comparison mode checks both entered values against the expected ratio. That is useful when field readings do not match design values. The custom ratio option helps with special cases, training examples, and unusual transformer references.
Power and Current Checks
The tool also estimates apparent power, real power, per phase power, and impedance. These values use the entered current and power factor. Apparent power is shown in volt-amperes. Real power is shown in watts. The impedance estimate is a quick load check. It is not a replacement for detailed design. Still, it helps users see how voltage and current relate in one clear table.
Neutral Current Review
Balanced three phase loads have little neutral current. Unbalanced loads create neutral current. This calculator uses the three entered phase currents to estimate the neutral current by vector relation. That helps identify uneven loading. It also helps explain why neutral conductors should not be ignored. Harmonics, non-linear loads, and local code rules may require more detailed study.
Practical Use
Use this calculator for quick planning, learning, and result documentation. It works well for panel checks, training sheets, and project notes. Enter realistic values. Compare the results with meter readings. Save the report when you need a record. Always treat electrical calculations with care. Confirm final designs with qualified professionals and applicable standards.
Frequently Asked Questions
1. What is line to neutral voltage?
It is the voltage measured between one live line conductor and the neutral conductor. In a wye system, this value is lower than line-to-line voltage because the phases are separated by angle.
2. What is the main three phase formula?
For a balanced three phase wye system, divide line-to-line voltage by the square root of three. The formula is VLN = VLL ÷ √3.
3. How do I calculate line-to-line from line-to-neutral?
Use the reverse formula. Multiply line-to-neutral voltage by the system ratio. For a balanced wye system, multiply by √3.
4. Why is 400 V often close to 230 V?
In a three phase wye system, 400 V divided by √3 equals about 230.94 V. This is why 400 V and 230 V are commonly related.
5. Can I use this for split phase systems?
Yes. Select split phase. The calculator divides the line-to-line value by 2. For example, 240 V becomes 120 V line to neutral.
6. What does comparison mode do?
Comparison mode uses both entered voltages. It calculates the measured ratio and compares the neutral value against the expected system value.
7. What is power factor?
Power factor shows how effectively electrical power is used. A value of 1 is ideal. Lower values reduce real power for the same apparent power.
8. Why enter current?
Current lets the calculator estimate apparent power, real power, phase power, and impedance. These values give a better view of the connected load.
9. What is neutral current?
Neutral current is the return current caused by unbalanced phase loads. If all phase currents are equal and balanced, neutral current is near zero.
10. Is this calculator for delta systems?
This page is mainly for wye, split phase, single phase, and custom ratio checks. Delta systems may need special handling depending on grounding.
11. Can I download the result?
Yes. After calculation, the result panel shows CSV and PDF buttons. Use them to save the current calculation report.
12. What does custom ratio mean?
Custom ratio lets you enter your own line-to-line to line-to-neutral ratio. It is useful for special examples or training situations.
13. Is the impedance result exact?
It is an estimate based on voltage divided by current. Real systems may include reactance, harmonics, temperature changes, and equipment behavior.
14. Can this replace professional electrical design?
No. It is a calculation aid. Always confirm final wiring, protection, conductor sizing, and safety requirements with qualified experts and local rules.