Transformer Winding Calculator

Transformer Winding Calculator. A transformer is an electrical device that transfers power between circuits by stepping voltage up or down through wound coils — and the Transformer Winding Calculator determines exactly how many turns each coil needs. Enter your transformer rating, number of phases, primary voltage, secondary voltage, and turns per volt to get the primary turns, secondary turns, turns ratio, primary and secondary currents, and transformer type. Also try the Transformer Turns Ratio Calculator.

Transformer Rating *

Rating Unit *

Number of Phases *

Primary Voltage *

Primary Voltage Unit *

Secondary Voltage *

Secondary Voltage Unit *

Turns per Volt *

Number of turns per volt for the transformer core

Results

Primary Turns

Secondary Turns

Turns Ratio

Primary Current

Secondary Current

Transformer Type

How do I calculate transformer turns ratio?

The turns ratio is calculated by dividing the primary voltage by the secondary voltage (Np/Ns = Vp/Vs). This ratio determines whether the transformer steps up or steps down voltage. See also our calculate Transformer Impedance.

What is the difference between step-up and step-down transformers?

A step-up transformer increases voltage from primary to secondary (turns ratio > 1), while a step-down transformer decreases voltage (turns ratio < 1). The type is determined by comparing primary and secondary voltages.

How do I determine the number of turns per volt?

Turns per volt depends on the transformer core material, cross-sectional area, and operating frequency. It's typically between 1-10 turns/volt for power transformers and can be calculated using the transformer equation V = 4.44 × f × N × Φ.

What factors affect transformer winding calculations?

Key factors include primary and secondary voltages, transformer rating (VA/kVA/MVA), number of phases, core material, operating frequency, and desired regulation. These determine the turns ratio and current ratings.

How do I calculate primary and secondary currents?

For single-phase: I = S/V, for three-phase: I = S/(√3 × V), where S is apparent power and V is voltage. The current is inversely proportional to voltage - higher voltage side has lower current.

What is the relationship between turns and current in a transformer?

Transformers follow the principle: Np/Ns = Vp/Vs = Is/Ip. This means the turns ratio equals the voltage ratio and is inversely proportional to the current ratio.

Can this calculator work for both single-phase and three-phase transformers?

Yes, the calculator handles both single-phase and three-phase transformers. For three-phase calculations, it uses the appropriate formulas that account for the √3 factor in power and current calculations.

What units can I use for transformer ratings and voltages?

The calculator supports multiple units: VA, kVA, MVA for power ratings, and V, kV, MV for voltages. Choose the appropriate units based on your transformer size and application. You might also find our calculate Transformer kVA Rating, Primary Current & Turns Ratio — Auto-Transformer useful.