Amps to VA Calculator
Convert amps to volt-amps (VA) for single-phase and three-phase circuits. Multiply current by voltage, and by √3 for three-phase.
APPARENT POWER
1,800 VA
IN kVA
1.8 kVA
FORMULA
VA = I × V
💡 How to Convert Amps to VA
To convert amps to VA on a single-phase circuit, multiply the current by the voltage. For three-phase, multiply by the line-to-line voltage and by √3 (≈ 1.732). The result is apparent power: the load your wiring, breaker, UPS or transformer must be able to carry.
Amps to VA formulas
Three-phase: VA = I × VL-L × √3
Worked examples
- US 15 A circuit: 15 A × 120 V = 1,800 VA.
- UK/EU 16 A circuit: 16 A × 230 V = 3,680 VA.
- 100 A three-phase supply at 400 V: 100 × 400 × 1.732 = 69,282 VA (about 69.3 kVA).
Amps to VA table
| Amps | 120 V | 230 V | 240 V | 208 V 3φ | 400 V 3φ | 480 V 3φ |
|---|---|---|---|---|---|---|
| 1 | 120 | 230 | 240 | 360 | 693 | 831 |
| 5 | 600 | 1,150 | 1,200 | 1,801 | 3,464 | 4,157 |
| 10 | 1,200 | 2,300 | 2,400 | 3,603 | 6,928 | 8,314 |
| 13 | 1,560 | 2,990 | 3,120 | 4,683 | 9,007 | 10,808 |
| 15 | 1,800 | 3,450 | 3,600 | 5,404 | 10,392 | 12,471 |
| 16 | 1,920 | 3,680 | 3,840 | 5,764 | 11,085 | 13,302 |
| 20 | 2,400 | 4,600 | 4,800 | 7,205 | 13,856 | 16,628 |
| 30 | 3,600 | 6,900 | 7,200 | 10,808 | 20,785 | 24,942 |
| 32 | 3,840 | 7,360 | 7,680 | 11,529 | 22,170 | 26,604 |
| 50 | 6,000 | 11,500 | 12,000 | 18,013 | 34,641 | 41,569 |
| 63 | 7,560 | 14,490 | 15,120 | 22,697 | 43,648 | 52,377 |
| 100 | 12,000 | 23,000 | 24,000 | 36,027 | 69,282 | 83,138 |
Sizing a UPS or inverter from amps
Measure or look up the current each device draws, multiply by your supply voltage, and add the results. Then choose a UPS or inverter with a VA rating comfortably above the total (many installers leave 20–25% headroom) and check that its watt rating also covers the real power of the load.
VA is not watts
Amps × volts gives VA, not watts, on AC circuits. To get real power, multiply by the power factor, or use the amps to kW calculator. On DC circuits there is no reactive power, so amps × volts gives watts directly.
Related conversions: VA to amps · amps to kVA · amps to watts