Transformer Current Calculator
Calculate approximate transformer full-load current on primary and secondary sides from transformer kVA, system voltage and phase configuration.
Primary full-load current23.1 A
Secondary full-load current601.4 A
How this tool works
Single-phase I = kVA × 1000 ÷ V. Three-phase I = kVA × 1000 ÷ (√3 × V).
Example
A 500 kVA three-phase transformer at 480 V secondary has a full-load current of about 601 A.
Common questions
Does impedance affect full-load current?
No. Nameplate kVA and voltage determine nominal full-load current. Impedance matters for fault-current calculations.
Does this size protection?
No. Protective-device sizing requires applicable code and equipment rules.