Transformer Input Form
Use the responsive calculator grid below.
Example Data Table
| Primary V | Primary Turns | Secondary Turns | Rating kVA | Load % | PF | Core Loss W | Copper Loss W | R % | X % | Loaded V2 | Efficiency % |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 230 | 1000 | 500 | 5 | 80 | 0.90 | 70 | 110 | 1.5 | 3.8 | 112.23 | 95.93 |
| 240 | 1200 | 600 | 10 | 100 | 0.85 | 120 | 220 | 1.8 | 4.2 | 113.13 | 96.52 |
| 120 | 800 | 200 | 1.5 | 60 | 0.95 | 25 | 48 | 1.2 | 2.9 | 29.38 | 95.68 |
Formula Used
Ideal ratio and voltage
Turns Ratio: a = Np / Ns
Ideal Secondary Voltage: Vs = Vp × (Ns / Np)
These equations link winding turns with transformed voltage.
Current and rating
Rated VA: S = kVA × 1000
Full Load Secondary Current: I2FL = S / Vs
Load Current: I2 = I2FL × Load Fraction
Voltage regulation
sin φ: √(1 − pf²)
Lagging: VR% = x(R%·pf + X%·sinφ)
Leading: VR% = x(R%·pf − X%·sinφ)
Losses and efficiency
Copper Loss at Load: Pcu = Pcu,FL × x²
Total Loss: Ploss = Pcore + Pcu
Efficiency: η = Pout / (Pout + Ploss) × 100
How to Use This Calculator
1. Enter winding data
Provide primary voltage, primary turns, and secondary turns to define the ideal voltage ratio.
2. Add rating values
Enter transformer rating, load percentage, and power factor so the calculator can estimate current and output power.
3. Include performance data
Fill core loss, copper loss, resistance, and reactance percentages for regulation and efficiency calculations.
4. Calculate and export
Press calculate to view results above the form, then export them as CSV or PDF.
Frequently Asked Questions
1. What does a single phase transformer calculator estimate?
It estimates turns ratio, secondary voltage, current, voltage regulation, copper loss, total loss, and efficiency from common design and operating inputs.
2. Why are primary and secondary turns needed?
Turns define the transformation ratio. That ratio directly determines ideal secondary voltage and the basic current relationship between windings.
3. What is voltage regulation?
Voltage regulation shows how much the secondary voltage changes between no-load and load conditions because of equivalent winding resistance and leakage reactance.
4. Why does copper loss change with load?
Copper loss depends on current squared. As load current rises, winding loss increases rapidly, which affects efficiency and heating.
5. What is the difference between lagging and leading load?
Lagging loads usually increase regulation, while leading loads can reduce it or even produce negative regulation under some conditions.
6. Is the secondary voltage exact in real service?
No. Real service voltage depends on regulation, temperature, frequency, losses, and how closely the equivalent resistance and reactance match reality.
7. Can this help with transformer sizing?
Yes. It helps compare expected current, voltage drop, and efficiency before selecting a transformer for a planned operating condition.
8. Does frequency affect transformer behavior?
Yes. Frequency influences core flux and magnetizing behavior. This calculator shows frequency for reference, but detailed magnetic design needs extra analysis.