Transformer Sizing Calculator
Free calculate the minimum transformer size required for single-phase or three-phase systems. determine kva rating based on load requirements.
Input Parameters
Recommended: 20-25%
Results
Enter parameters to calculate transformer size
Transformer Sizing Formulas
Single-Phase
kVA = (V × I) / 1000
Where V = voltage, I = current
Three-Phase
kVA = (√3 × V × I) / 1000
Where V = line voltage, I = line current
With Safety Factor
kVA_required = kVA × (1 + SF/100)
Where SF = safety factor percentage
Standard Sizes
- • 5, 10, 15, 25, 37.5 kVA
- • 50, 75, 100, 167 kVA
- • 250, 333, 500, 750 kVA
- • 1000+ kVA (larger sizes)