Amps to kVA Calculator
This amps to kVA calculator converts amps to kVA and kVA to amps for single-phase and three-phase systems. Enter the current and voltage to convert amps to kVA, or switch it around and the kVA to amps calculator gives you the current. It is the fast way to size transformers, generators, and cables.
Results
The Amps to kVA Calculator is part of our AC & Three Phase collection. Browse more ac & three phase to size, convert, and check your work alongside this tool.
What the amps to kVA calculator does
The amps to kVA calculator converts between current and apparent power in both directions. Convert amps to kVA and you learn how much apparent power a load draws; run the kVA to amps conversion and you get the current a transformer or generator will deliver. Because so many people search for kVA to amps rather than the other way round, this tool is built as a two-way amp convert to kVA and kVA to amps calculator, covering single-phase and three-phase alike.
Amps to kVA and kVA to amps formula
To convert amps to kVA on a single-phase supply, multiply volts by amps and divide by 1000. Three-phase adds the square root of three:
The kVA to amps formula three phase simply rearranges this to solve for current, which is the ampere to kVA calculation run in reverse:
Amps to kVA conversion example
A three-phase load drawing 14.43 amps at 400 volts, converted with the amps to kVA calculator:
Now reverse it. The kVA to amps calculation of 10 kVA at 400 volts three-phase returns 14.43 amps, which confirms the amp to kVA conversion works cleanly in both directions.
How to use the amps to kVA calculator
Pick single-phase or three-phase, then enter the two values you have. To convert amps to kVA, enter the current and voltage. To go the other way, the kVA to amps calculator takes apparent power and voltage and returns the current. For any three phase kVA to amps job, use the line-to-line voltage and the tool applies the correct kVA to amps formula three phase automatically.
Reading the amps to kVA result
The kVA figure is the apparent power your supply must provide, so size transformers and generators to it and add a margin for motor starting. When you convert kVA to amps instead, the current sets your cable and breaker size. Remember the amps to kVA calculator gives apparent power, not real power: the working kW equals the kVA times the power factor, which matters when you calculate amps to kVA for a motor.
When to convert amps to kVA
- Sizing a generator with the generator kVA to amps calculator
- Rating a transformer using the transformer kVA to amps calculator
- Running a three phase kVA to amps conversion on an industrial supply
- Checking full-load current for a 1000 kVA to amps job
- Confirming a supply can carry a new load by converting amps to kVA
Common amps to kVA conversion mistakes
- Using phase voltage for three-phase. Always enter line-to-line voltage, or the three phase kVA to amps result is wrong.
- Treating kVA as kW. The amps to kVA conversion gives apparent power; real power needs the power factor.
- Forgetting motor inrush. Motors draw far more than running current at startup, so size above the kVA to amps figure.
Tips for accurate amps to kVA results
- Read the nameplate current for the most reliable amp to kVA conversion.
- Use line-to-line voltage for every three phase kVA to amps calculation.
- Size generators on the kVA figure, then add a starting margin before you convert kVA to amps for the cable.
Why kVA to amps matters as much as amps to kVA
Most people reach for this tool to convert kVA to amps, not the reverse, because equipment is rated in kVA but installed with cable and breakers rated in amps. A transformer nameplate says 500 kVA; the electrician needs the amps to size the feeder. That is why the transformer kVA to amps calculator and generator kVA to amps calculator directions get the most use. Converting amps to kVA is the design-side question, while kVA to amps is the install-side question, and a good amps to kVA calculator answers both without you rearranging a formula.
Why three-phase changes the ampere to kVA calculation
The kVA to amps formula three phase includes the square root of three because power is delivered across three conductors offset by 120 degrees. The same apparent power arrives at a lower current per conductor, so a three phase kVA to amps conversion of a large rating like 1000 kVA gives a far smaller current than the single-phase equivalent. This is exactly why industrial sites use three-phase for big loads, and why the kVA to amps chart above shows the three-phase column running roughly one-third of the single-phase current for the same kVA.
kVA to amps chart
A quick kVA to amps chart for common ratings, both single-phase (230 V) and three-phase (400 V):
| kVA | Amps @230V 1-phase | Amps @400V 3-phase |
|---|---|---|
| 1 kVA | 4.3 A | 1.4 A |
| 10 kVA | 43.5 A | 14.4 A |
| 100 kVA | 435 A | 144 A |
| 1000 kVA | 4348 A | 1443 A |
Amps to kVA Calculator FAQ
How do I convert amps to kVA?
Multiply voltage by current and divide by 1000 for single-phase; add the square root of three for three-phase. The amps to kVA calculator does both, and it reverses to a kVA to amps conversion when you need current instead.
How do I convert kVA to amps?
Divide kVA times 1000 by the voltage (for three-phase, by √3 times the voltage). This kVA to amps calculation is the amp convert to kVA process run backward, and the calculator handles it in one click.
What is the kVA to amps formula for three phase?
Current equals kVA times 1000 divided by (√3 times the line-to-line voltage). The amps to kVA calculator applies this kVA to amps formula three phase automatically once you select three-phase.
How many amps is 1000 kVA?
At 400 V three-phase, 1000 kVA is about 1443 amps; at 230 V single-phase it is around 4348 amps. See the kVA to amps chart above, or run the exact figure in the calculator.
Is kVA the same as kW?
No. The amps to kVA calculator gives apparent power in kVA, while kW is real power. Multiply the kVA result by the power factor to get kW.