Transformer Secondary Voltage Calculator
Calculate transformer secondary voltage with transparent engineering inputs and the displayed formula.
Run deterministic checks for missing or mixed units, physical bounds, detectable out-of-range values and formula applicability. This is not an engineering approval or a complete code/compliance check.
Export the current calculation inputs and outputs with formula, assumptions, confirmed source credits, automated verification status, tool version and timestamp.
PROFENG Pro unlocks calculation-record exports. The calculation itself remains free.
PROFENG provides this tool for engineering screening and educational use. Check the calculation basis, units, physical assumptions, applicable standards, safety factors, equipment data and project-specific requirements before design, procurement or operation.
Turn this result into a calculation record
Carry the tool context into the PROFENG calculation-check and record workspace without implying certification or engineering approval.
Why use this transformer secondary voltage calculator?
Calculate transformer secondary voltage with transparent engineering inputs and the displayed formula. The displayed relationship is V₂ = V₁ N₂/N₁.
What this calculation does
This calculator determines secondary voltage from primary voltage, primary turns, secondary turns. Use it for transparent electrical screening calculations before equipment selection, protection studies or detailed circuit analysis.
Formula and engineering variables
V₂ = V₁ N₂/N₁
| Variable | Definition | Unit | Working guidance |
|---|---|---|---|
primaryV | Primary voltage | V | Illustrative screening band: 0 to about 4,000 V. This is not a design limit. |
primaryN | Primary turns | turns | Illustrative screening band: 0 to about 10,000 turns. This is not a design limit. |
secondaryN | Secondary turns | turns | Illustrative screening band: 0 to about 2,500 turns. This is not a design limit. |
Ranges above are screening guidance or physical bounds where stated. They are not code limits or manufacturer ratings.
Calculated outputs
- Secondary voltage (V): primaryV*secondaryN/primaryN
Worked example
- Primary voltage (primaryV) = 400 V
- Primary turns (primaryN) = 1,000 turns
- Secondary turns (secondaryN) = 250 turns
(400)*(250)/(1000) = 100 VSecondary voltage: 100 VAssumptions
- The entered quantities describe the same electrical operating state.
- AC quantities are interpreted using the formula's stated phase and power-factor assumptions.
- Nominal values do not represent transient, fault or harmonic behavior unless explicitly included.
Limitations
- Protection, conductor ampacity, harmonics, starting duty, insulation coordination and equipment ratings require separate checks.
- Final electrical design must follow the applicable installation and equipment standards.
- Transformer is treated as ideal for the voltage-ratio relationship.
- Winding drops, regulation, losses, leakage impedance and tap effects are not represented.
- The displayed default values are a worked example only; replace them with traceable project or measurement data.
Formula source and acknowledgement
Relationship used: For an ideal transformer, V2/V1 = N2/N1.
The relationship used here follows Stephen J. Chapman, Electric Machinery Fundamentals 5th edition (2011), McGraw Hill.
Credit for the underlying method belongs to the cited author(s). PROFENG presents its own implementation and wording and is not affiliated with or endorsed by the authors or publishers.
Limits of use for this relationship
- Transformer is treated as ideal for the voltage-ratio relationship.
- Winding drops, regulation, losses, leakage impedance and tap effects are not represented.
Read the PROFENG methodology for formula sourcing and automated checks →
How to use it
Start with the inputs shown above, review the assumptions or options, then generate the result. Where the tool creates a file, keep the original until you have opened and checked the downloaded output.
Frequently asked questions
What does Transformer Secondary Voltage Calculator calculate?
This calculator determines secondary voltage from primary voltage, primary turns, secondary turns. Use it for transparent electrical screening calculations before equipment selection, protection studies or detailed circuit analysis.
What formula does Transformer Secondary Voltage Calculator use?
The calculator uses V₂ = V₁ N₂/N₁. Every input used by the implementation is listed in the variable table on this page.
How is the worked example for Transformer Secondary Voltage Calculator checked?
PROFENG substitutes the displayed default values into the implemented relationship and compares the result against automated verification cases where an independent verifier is available.
What assumptions matter most for Transformer Secondary Voltage Calculator?
The entered quantities describe the same electrical operating state. AC quantities are interpreted using the formula's stated phase and power-factor assumptions. Nominal values do not represent transient, fault or harmonic behavior unless explicitly included.
Can I use this result for final design or procurement?
Use it as an engineering screening calculation. Final design, procurement, operation or compliance decisions require project-specific data and the applicable engineering method, standard or manufacturer information.
QA, changelog and corrections
Last QA update: 30 September 2026.
Automated verification passed – 30 September 2026 – six numerical cases checked, with dimensional checks, independent cross-checks for calculators, and unit round-trip checks for converters where applicable.
Changelog
30 September 2026 – source/indexation status, metadata and correction pathway reviewed. Engineering tools display the automated verification label only when they are inside the passing Part 3 verification scope.