Electrical reference chart
kVA to Amps Chart
Translate transformer kVA, UPS kVA, generator kVA, or panel schedule apparent load into line current for common U.S. voltage systems.
Quick reference table
For transformer and distribution work, kVA-to-amps is a line-current screen. 45 kVA at 480 V 3-phase gives about 54.1 A, while 15 kVA at 240 V 1-phase gives 62.5 A. Single-phase current uses kVA x 1000 divided by voltage. Balanced three-phase current uses kVA x 1000 divided by 1.732 x line-to-line voltage. Use the calculator after the chart when the result will feed a transformer schedule, feeder review, load bank setup, or equipment submittal.
Transformer kVA to full-load current screen
| kVA | 120 V 1-phase | 240 V 1-phase | 208 V 3-phase | 480 V 3-phase |
|---|---|---|---|---|
| 3 | 25.0 A | 12.5 A | 8.3 A | 3.6 A |
| 15 | 125.0 A | 62.5 A | 41.6 A | 18.0 A |
| 30 | 250.0 A | 125.0 A | 83.3 A | 36.1 A |
| 45 | 375.0 A | 187.5 A | 124.9 A | 54.1 A |
| 75 | 625.0 A | 312.5 A | 208.2 A | 90.2 A |
| 112.5 | 937.5 A | 468.8 A | 312.3 A | 135.3 A |
Where the converted amps usually go next
| Work context | Use the amps for | Do not skip |
|---|---|---|
| Transformer schedule | Primary or secondary current reference | Nameplate taps and impedance notes |
| Temporary load bank | Cable set and meter range planning | Cam-lock, lug, and equipment ratings |
| Panel or switchboard review | Apparent-load comparison | Available fault current and bus rating |
| Generator or UPS submittal | Output current cross-check | Manufacturer derating and connection details |
kVA-to-amps chart to calculator handoff
| Search or worksheet need | Use this chart for | Open the calculator when |
|---|---|---|
| kVA to amps chart | Screening transformer, UPS, generator, or apparent-load current | Voltage, phase, and equipment role need a traceable calculation |
| Transformer kVA to amps | Checking common full-load current rows before a schedule review | Primary and secondary sides, taps, or impedance notes must stay attached |
| Single-phase vs three-phase kVA amps | Confirming which formula and voltage basis apply | Line-to-line voltage, phase, or balanced-load assumptions are not obvious |
| kVA amps to watts comparison | Keeping apparent current separate from real-power estimates | Power factor or kW must be compared against the apparent-power basis |
How to use this chart
Identify the kVA source
Start by naming the source of the kVA value: transformer nameplate, UPS output, generator rating, equipment submittal, or load schedule total.
Match voltage and phase exactly
Use single-phase voltage for single-phase loads and line-to-line voltage for balanced three-phase loads. Do not mix line-to-neutral voltage into a three-phase formula.
Carry the result into the next review
After the current is calculated, use the calculator output as an input for feeder, lug, protection, metering, and equipment-rating checks.
Keep nameplate details attached
Record transformer taps, UPS overload data, generator derating, or manufacturer notes beside the amperes so the number is not separated from the equipment.
Formula basis
Single phase: A = kVA x 1000 / V. Three phase: A = kVA x 1000 / (1.732 x VLL).
- 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.
Worked examples
45 kVA dry-type transformer at 480 V three-phase
45 x 1000 / (1.732 x 480) = about 54.1 A on the 480 V side before feeder, protection, and terminal checks.
15 kVA single-phase load at 240 V
15 x 1000 / 240 = 62.5 A. Treat that as apparent-load current, not as a finished breaker or conductor selection.
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Frequently asked questions
These answers explain how to use the chart without turning a quick reference into a final design decision.