20 kVA to Amps
Find current directly from apparent power and line voltage for single and three-phase systems.
Operating a 20 kVA industrial load requires careful amp calculation. It draws 83.33 Amps on standard 240V single-phase lines. For commercial three-phase power, expect 55.51 Amps at 208V and 24.06 Amps at 480V.
20 kVA is 83.33 A at 240 V single-phase AC. At other common voltages — 208 V: 96.15 A. Use the calculator below for any voltage or circuit type.
For three-phase systems, the current is lower because the power is distributed across three alternating current waves. This relies on the
Amps = (kVA × 1000) ÷ (Volts × 1.732).
| Phase & Voltage | Max Current (Amps) |
|---|---|
| Single-phase 120V | 166.67 A |
| Single-phase 240V | 83.33 A |
| Three-phase 208V | 55.51 A |
| Three-phase 480V | 24.06 A |
How do you convert kVA to amps?
For single-phase, amps = (kVA × 1000) ÷ V. A 10 kVA single-phase supply at 240 V gives (10 × 1000) ÷ 240 = 41.7 A. For three-phase, amps = (kVA × 1000) ÷ (√3 × V): a 10 kVA, 400 V three-phase supply gives 10000 ÷ (1.732 × 400) = 14.4 A.
kVA to Amps Formula
Multiply kVA by 1,000 to convert to VA (volt-amps), then divide by the line voltage. This gives the current in amps for a single-phase system. Example: 5 kVA at 120 V to (5,000) ÷ 120 = 41.67 A.
For three-phase, divide by voltage and the square root of 3 (≈ 1.7321). The √3 factor arises from the 120° phase angle between conductors. Use line-to-line voltage (e.g. 400 V, 480 V). Example: 5 kVA at 400 V to 5,000 ÷ (400 × 1.7321) = 7.22 A.
kVA to Amps Reference Table — Single-phase
| kVA | Amps @ 120 V | Amps @ 240 V |
|---|---|---|
| 1 kVA | 8.3333 A | 4.1667 A |
| 2 kVA | 16.6667 A | 8.3333 A |
| 5 kVA | 41.6667 A | 20.8333 A |
| 10 kVA | 83.3333 A | 41.6667 A |
| 20 kVA | 166.6667 A | 83.3333 A |
| 50 kVA | 416.6667 A | 208.3333 A |
Single-phase vs Three-phase
One live conductor plus a neutral. Power is delivered as a single sinusoidal wave. Common in homes, small offices, and retail units up to around 10 kVA. Higher current per conductor for the same power.
A = (kVA × 1,000) ÷ VThree live conductors, each offset 120° apart. Delivers three times the power at the same current, making it ideal for motors, data centres, and industrial sites. Far more efficient for loads above 10 kVA.
A = (kVA × 1,000) ÷ (V × √3)In practice: a 20 kVA rack row
Twenty kVA is 55.5 A per phase at 208 V three-phase, about what feeds a small row of server racks. Balance matters more than the total here: loading one phase to 55 A while the others sit at 30 A will trip protection and stress the supply even though the aggregate stays within rating. Metered PDUs exist largely to make that imbalance visible before it becomes an outage.
Frequently Asked Questions
Multiply kVA by 1,000 and divide by the voltage. For
single-phase: A = (kVA × 1,000) ÷ V.
For three-phase: A = (kVA × 1,000) ÷ (V × √3).
For example, 10 kVA at 240 V single-phase gives
(10 × 1,000) ÷ 240 = 41.67 A.
- Single-phase:
A = (kVA × 1,000) ÷ V - Three-phase:
A = (kVA × 1,000) ÷ (V × √3), where √3 ≈ 1.7321
Note that kVA is apparent power — it does not account for power factor, unlike kW (real power). Use kVA when sizing cables, fuses, and switchgear.
- Single-phase at 240 V: (5 × 1,000) ÷ 240 = 20.83 A
- Three-phase at 240 V (L-L): (5 × 1,000) ÷ (240 × 1.7321) = 12.03 A
Three-phase draws less current per conductor because load is shared across three wires.
Single-phase power uses one live conductor and a neutral, delivering power as a single sinusoidal wave. It is standard in homes and small offices. Three-phase power uses three live conductors, each carrying a wave offset by 120°. For the same kVA, three-phase requires significantly less current per conductor, making it more efficient for large motors, industrial equipment, and commercial buildings.