Electrical Calculators
Transformer Sizing
Calculate primary and secondary full-load current.
01
Inputs
02
Result & worksheet
90.2 A full-load current
Recorded summary
- 75 kVA
- 480 V
- Three-phase
- FLC: 90.2 A
Formula used
I = kVA × 1,000 ÷ V (1φ) or ÷ (√3 × V) (3φ)Calculation steps
- 75 kVA × 1,000 ÷ (√3 × 480 V)
Assumptions
- Rated kVA at full load
- Balanced three-phase load
- This does not size protection, conductors, or secondary taps
Verify before use
- Nameplate voltage, kVA, impedance, temperature rise, and connections
- Primary and secondary protection rules
- Secondary conductor and grounding/bonding requirements
- Available fault current and equipment ratings