I = P / VNo power factor needed for DC circuits.
Find the current in amps for a 300 watt load. Select the circuit voltage and system type below — DC, single-phase AC, or three-phase AC — and the calculator shows the result instantly. The table below lists results at common voltages.
Power factor varies by load. Use the equipment value when available.
I = P / VCustom voltage is always supported.
Results at common voltages. AC values use power factor = 0.9.
| Voltage | DC (I = P/V) | AC 1φ (PF 0.9) | AC 3φ (PF 0.9) |
|---|---|---|---|
| 12 V | 25 A | 27.7778 A | 16.0375 A |
| 24 V | 12.5 A | 13.8889 A | 8.0188 A |
| 48 V | 6.25 A | 6.9444 A | 4.0094 A |
| 120 V | 2.5 A | 2.7778 A | 1.6038 A |
| 240 V | 1.25 A | 1.3889 A | 0.801875 A |
I = P / VNo power factor needed for DC circuits.
I = P / (V × PF)Single-phase AC — multiply voltage by power factor.
I = P / (√3 × V × PF)Three-phase AC — divide by √3 ≈ 1.732.
DC or resistive: 300 / 120 = 2.5 A. Single-phase AC at PF 0.9: 300 / (120 × 0.9) = 2.7778 A.
DC or resistive: 300 / 240 = 1.25 A. Single-phase AC at PF 0.9: 300 / (240 × 0.9) = 1.3889 A.
DC: 300 / 12 = 25 A. This is common for 12V battery and solar systems.