kVA to Amps Calculator
Convert kilovolt-amps (kVA) to amps (A) for single-phase and three-phase power, at any voltage — the same calculation used to size generators, transformers and breakers.
Balanced three-phase load, line-to-line voltage. Change any value and the result updates instantly.
The kVA to amps formulas
Current follows directly from apparent power and voltage. Single-phase divides by the voltage once; three-phase also accounts for the power being shared across three conductors. The three-phase kVA to amps calculator adds a line-to-neutral mode for systems specified that way.
For one live conductor — homes, small appliances, single-phase generators and UPS units.
The standard three-phase formula, using the line-to-line voltage (400V, 480V) found on most nameplates.
Used when the voltage given is line-to-neutral (for example 230V in a 400V system) instead of line-to-line.
Why there is no power factor in this formula
Power factor converts kVA into kW — it separates apparent power from real power. Current is not part of that step: once you know the apparent power (kVA) and the voltage, the current follows on its own. Carry the same load through kVA → kW → amps and the power factor cancels out exactly, which is the proof it never belonged here.
If a calculator asks for power factor to turn kVA into amps, it is silently answering the kW question instead — and its result will be too high by exactly that factor. This site never asks for one. The full derivation is on the methodology page.
Quick answers
The conversions people look up most, answered outright. Every figure below comes from the same formulas as the calculator — nothing is rounded from a neighbouring value.
kVA to amps conversion chart
The most common ratings at the three voltages electricians ask about most. The full kVA to amps chart covers every standard rating from 0.5 to 3,000 kVA at 120, 208, 240, 400 and 480 volts.
| kVA | 240V · single-phase | 400V · three-phase | 480V · three-phase |
|---|---|---|---|
| 1 | 4.17 A | 1.44 A | 1.20 A |
| 5 | 20.83 A | 7.22 A | 6.01 A |
| 10 | 41.67 A | 14.43 A | 12.03 A |
| 25 | 104.17 A | 36.08 A | 30.07 A |
| 50 | 208.33 A | 72.17 A | 60.14 A |
| 100 | 416.67 A | 144.34 A | 120.28 A |
| 250 | 1,041.67 A | 360.84 A | 300.70 A |
| 500 | 2,083.33 A | 721.69 A | 601.41 A |
Related calculators
Every conversion in the kVA sizing job, each with its own worked examples and charts. If you are starting from a measured or nameplate current instead, the amps to kVA calculator runs the same math backwards. Generator work has its own generator kVA to amps calculator with standard genset sizes loaded, and transformer nameplates are covered by the transformer kVA to amps calculator, which reads both sides of the unit at once.
Amps to kVA Calculator
Working from a measured or nameplate current? Convert amps back to kVA in either phase.
Open calculator →Three-Phase kVA to Amps
A dedicated three-phase tool with line-to-line and line-to-neutral modes, built for 400V and 480V systems.
Open calculator →Generator kVA to Amps
Full-load amps for standard genset ratings, with the DG and diesel-generator sizes preloaded.
Open calculator →Transformer kVA to Amps
Primary and secondary full-load amps straight from the transformer nameplate kVA.
Open calculator →kVA to Amps Chart
The printable master chart: every standard kVA rating at 120, 208, 240, 400 and 480 volts.
See the chart →Worked examples
Three everyday jobs, done step by step with the same formulas the calculator uses.
A 75 kVA transformer on a 480V three-phase supply: 75,000 ÷ (√3 × 480) = 75,000 ÷ 831.38 — so its full-load current is 90.21 A per phase. That is the figure you size the breaker and feeder cable against. The transformer calculator also works out the primary side at the same time.
A 20 kVA single-phase generator feeding a 240V panel: 20,000 ÷ 240 gives a full-load current of 83.33 A. Every load on that panel shares those amps, which is why the generator calculator lists standard genset sizes with their full-load amps side by side.
A 10 kVA UPS on a 208V three-phase supply: 10,000 ÷ (√3 × 208) = 10,000 ÷ 360.27 — a full-load current of 27.76 A. UPS units are rated in kVA for exactly this reason: the rating already describes the current the output can carry at its rated voltage.
When to be careful
The conversion itself is exact. The situations below are where a correct number still needs a second thought before it becomes a decision.
Balanced loads
The three-phase formulas assume the load is balanced — shared evenly across the three phases, which is how the kVA rating is defined. A heavily unbalanced load can push one phase above the figure shown here while the others sit below it. For unbalanced panels, work out each phase's single-phase current separately.
Nameplate kVA vs measured current
A nameplate kVA is a maximum rating, not a promise about what a running machine draws moment to moment. Equipment at part load draws less. If you are checking an existing circuit, a clamp meter reading is the truth; this conversion tells you what the circuit must be able to carry at full rating.
Breakers and cables need more than this number
Full-load amps is the starting point for sizing protection and conductors, not the whole job. Continuous-load rules, derating for temperature and conduit fill, and inrush current all come from the National Electrical Code and the equipment manual. Use the figure here to plan, then verify the installation against the code — or have a licensed electrician do it.
Frequently asked questions
How many amps are in 1 kVA?
It depends on the voltage and the phase, because amps = kVA × 1000 ÷ volts. At 240 V single-phase, 1 kVA is 4.17 A. At 400 V three-phase it is 1.44 A, and at 480 V three-phase it is 1.20 A. There is no single answer without a voltage — a chart that gives one without asking for volts is guessing.
How many kVA is 50 amps?
At 240 V single-phase, 50 A is 12.00 kVA. At 400 V three-phase, 50 A is 34.64 kVA, and at 480 V three-phase it is 41.57 kVA. Pick the row that matches your supply — the amps to kVA calculator runs the reverse conversion for any voltage.
What is 10 kVA in amps?
At 240 V single-phase, 10 kVA is 41.67 A. At 400 V three-phase it is 14.43 A, and at 480 V three-phase it is 12.03 A. The same 10 kVA pulls very different currents depending on the supply, which is why the voltage always comes first in this conversion.
How to calculate kVA in 3-phase?
For three-phase, amps = kVA × 1000 ÷ (√3 × line-to-line volts). Example: 100 kVA at 400 V is 100,000 ÷ (1.732 × 400) = 144.34 A. Going the other way, kVA = √3 × amps × volts ÷ 1000. If your voltage is line-to-neutral instead of line-to-line, divide by 3 × volts rather than √3 × volts.
Does power factor change a kVA to amps conversion?
No. Power factor converts kVA into kW — it separates apparent power from real power — and it never enters the kVA to amps formula, which uses only apparent power and voltage. If a calculator asks for a power factor when converting kVA to amps, it is really answering the kW question, and at a power factor of 0.8 its result will be 25% too high.
Can I convert kVA to amps for DC?
No. kVA is an AC quantity: apparent power exists because AC current and voltage alternate, and the gap between them is what power factor describes. A DC circuit is specified in watts and amps directly, where amps = watts ÷ volts. If a DC device is labelled in VA, treat that figure as watts for the current calculation.
Sources and references
The formulas and voltage levels on this page rest on the following standards. The methodology page shows the derivations in full.
- NFPA 70 — National Electrical Code (NEC) — the code electricians size conductors and protection against
- IEEE Std 141 — Recommended Practice for Electric Power Distribution (Red Book) — apparent power and load-current practice for industrial and commercial systems
- IEC 60038 — Standard Voltages — the standard voltage levels (120, 208, 240, 400, 480 V) used across this site
- NIST — SI unit of electric current (the ampere) — the definition of the ampere behind every result