Transformer worksheet
kVA and Amps Calculator
Convert between apparent power and current; 45 kVA at 480 V 3-phase gives 54.1 A, while 15 kVA at 240 V 1-phase gives 62.5 A.
Convert kVA and Amps
Convert between apparent power and current for transformer, generator, UPS, and load schedule worksheets: 45 kVA at 480 V 3-phase gives 54.1 A, while 15 kVA at 240 V 1-phase gives 62.5 A.
Result
Amps
90.21 A
Result notes. Keep inputs, assumptions, and result together before using this value in project records.
Keep the entered values, assumptions, and result together when adding this calculation to job notes or submittal records. Final installation choices should align with the applicable code edition, equipment listing, manufacturer instructions, local amendments, and AHJ requirements.
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Formula and field context
Convert between apparent power and current; 45 kVA at 480 V 3-phase gives 54.1 A, while 15 kVA at 240 V 1-phase gives 62.5 A.
Formula context
kVA to Amps Chart
For transformer and distribution work, kVA-to-amps is a line-current screen that must stay tied to voltage, phase, primary or secondary side, and equipment role. Use the chart to confirm the formula family, then open the transformer calculator when the current will feed a transformer schedule, feeder review, load-bank setup, or equipment submittal.
Formula
Single phase: A = kVA x 1000 / V. Three phase: A = kVA x 1000 / (1.732 x VLL).Variables to keep with the result
- A is line current in amperes.
- kVA is apparent power from the transformer, UPS, generator, or load schedule.
- V is circuit voltage for single-phase work.
- VLL is line-to-line voltage for balanced three-phase systems.
Formula and voltage basis
For single-phase apparent power, amps equals kVA times 1,000 divided by volts. For balanced three-phase equipment, amps equals kVA times 1,000 divided by the square root of 3 and line-to-line volts. This is why a 75 kVA transformer has a different full-load current at 208 V than it does at 480 V.
Where electricians use it
This conversion is common when reviewing transformer secondary current, generator load, UPS output, and commercial load schedules. It supports field documentation before opening a full transformer or generator calculator, especially when the nameplate is written in kVA instead of kW.
Limits and escalation
The result is an apparent-power current, not a short-circuit study, conductor selection, or overcurrent-device setting. Use the transformer calculator for full-load current and voltage relationship review, and use the transformer impedance or short-circuit calculator when available fault current matters.