kVA to Amps
Converting kVA to amps is a routine task when sizing circuit breakers, selecting transformers, or planning an electrical load. The conversion depends on voltage and whether the supply is single-phase or three-phase. This guide gives you the exact formulas, a built‑in calculator, and a quick reference table to get the current in amperes in seconds.
Quick Reference Table
| kVA | Single-Phase 120 V (A) | Single-Phase 240 V (A) | Three-Phase 208 V (A) | Three-Phase 480 V (A) |
|---|---|---|---|---|
| 1 | 8.33 | 4.17 | 2.78 | 1.20 |
| 5 | 41.67 | 20.83 | 13.88 | 6.01 |
| 10 | 83.33 | 41.67 | 27.76 | 12.03 |
| 25 | 208.33 | 104.17 | 69.40 | 30.06 |
| 50 | 416.67 | 208.33 | 138.80 | 60.13 |
| 100 | 833.33 | 416.67 | 277.60 | 120.28 |
| 200 | 1,666.67 | 833.33 | 555.20 | 240.56 |
The calculator accepts kilovolt‑amperes and voltage values, then instantly outputs the resulting current for single‑phase or three‑phase configurations.
kVA to Amps Conversion Formulas
The relationship between apparent power (kVA), voltage (V), and current (A) changes with the number of phases.
Single‑Phase Formula
For a single‑phase circuit, use the line‑to‑neutral voltage:
I (A) = (kVA × 1,000) ÷ V
Where:
- I = current in amperes
- kVA = apparent power in kilovolt‑amperes
- V = line‑to‑neutral voltage
Three‑Phase Formulas
Three‑phase systems can be calculated using line‑to‑line or line‑to‑neutral voltage.
Line‑to‑line voltage:
I (A) = (kVA × 1,000) ÷ (√3 × V_LL)
or simply
I (A) = (kVA × 1,000) ÷ (1.732 × V_LL)
Line‑to‑neutral voltage:
I (A) = (kVA × 1,000) ÷ (3 × V_LN)
Note that V_LN = V_LL ÷ √3, so both methods give identical results.
Practical Examples
Example 1 – Single‑phase load
A 5 kVA appliance connected to a 230 V single‑phase supply draws:
I = 5 × 1,000 ÷ 230 = 21.74 amps
Example 2 – Three‑phase transformer
A 100 kVA transformer on a 480 V three‑phase system (line‑to‑line) carries:
I = 100 × 1,000 ÷ (1.732 × 480) ≈ 120.28 amps
kVA to Amps Quick Reference Table
| kVA | Single‑Phase 120 V (A) | Single‑Phase 240 V (A) | Three‑Phase 208 V (A) | Three‑Phase 480 V (A) |
|---|---|---|---|---|
| 1 | 8.33 | 4.17 | 2.78 | 1.20 |
| 5 | 41.67 | 20.83 | 13.88 | 6.01 |
| 10 | 83.33 | 41.67 | 27.76 | 12.03 |
| 25 | 208.33 | 104.17 | 69.40 | 30.06 |
| 50 | 416.67 | 208.33 | 138.80 | 60.13 |
| 100 | 833.33 | 416.67 | 277.60 | 120.28 |
| 200 | 1,666.67 | 833.33 | 555.20 | 240.56 |
All three‑phase values assume line‑to‑line voltage.
How Many Amps in 1 kVA?
The current for 1 kVA depends entirely on voltage and phase arrangement. For a 120 V single‑phase circuit, 1 kVA equals 8.33 amps. At 240 V single‑phase, it drops to 4.17 amps. On a three‑phase 208 V (line‑to‑line) system, 1 kVA draws about 2.78 amps, while on 480 V three‑phase it draws roughly 1.2 amps. Always check the actual voltage before estimating the current.
kW vs. kVA – Why It Matters
Real power (kW) is the energy actually consumed, while apparent power (kVA) includes reactive power that flows back and forth in inductive or capacitive loads. The power factor (PF) links them:
kW = kVA × PF
Most residential appliances have a PF close to 1.0, but motors, fluorescent lights, and transformers often have power factors between 0.8 and 0.95. Equipment like UPS units and cables are rated in kVA because they must handle the total current regardless of PF. When you convert kVA to amps, you find the full current the circuit must support, making it critical for safe conductor and breaker sizing.