Power & phase
Watts to Amps Calculator
Current equals real power divided by voltage for DC, with power factor and the square-root-of-three phase factor added for AC modes. Enter the voltage and phase relationship used by the load.
Convert watts to current for DC, single-phase AC, and three-phase AC with explicit power factor.
Calculated result
Calculated current
Calculating…
Calculated locally in your browser
Planning math only. Verify equipment specifications and installation requirements separately.
What this calculator returns
Check whether the equipment rating is input or output power and use its stated power factor.
Formula and variables
The calculation runs entirely in your browser. Static formulas, definitions, examples, and tables remain readable without JavaScript.
I = P/V (DC); I = P/(V × PF) (1φ); I = P/(√3 × VLL × PF) (3φ).
- P
- Real power, in watts or kilowatts.
- S
- Apparent power, in volt-amperes or kilovolt-amperes.
- V
- RMS voltage; line-to-line voltage in three-phase modes.
- I
- Line or circuit current, in amperes.
- PF
- Power factor, expressed as a ratio from greater than zero through one.
- Q
- Reactive power, in volt-amperes reactive.
P is real power, V is voltage, PF is power factor, and VLL is line-to-line voltage.
Worked example
| Input | Value |
|---|---|
| System type | Single-phase AC |
| Real power | 2400 W |
| Voltage | 120 V |
| Result | 2,400 W at 120 V and PF 1 is 20 A in DC or single-phase AC. |
2,400 W at 120 V and PF 1 is 20 A in DC or single-phase AC.
Reference table
| Voltage | Amps at 1 kW | Amps at 5 kW | Watts at 10 A |
|---|---|---|---|
| 120 V | 8.33 A | 41.67 A | 1,200 W |
| 208 V | 4.81 A | 24.04 A | 2,080 W |
| 240 V | 4.17 A | 20.83 A | 2,400 W |
| 480 V | 2.08 A | 10.42 A | 4,800 W |
Frequently asked questions
Is this watts-to-amps result code compliant?
No. PowerTotals performs transparent electrical math and planning estimates. Installation decisions must be checked against equipment documentation, the adopted code, and the authority having jurisdiction.
Are my inputs uploaded?
No. Calculations run locally in your browser, and analytics never receives raw electrical values.
Why does AC need power factor?
Real power can be lower than apparent power, so current depends on PF for many AC loads.
Assumptions and limitations
- No breaker or conductor recommendation.
- Balanced three-phase system assumed.
Method and sources
Read the calculation methodology, review the technical sources, or browse the reference table index. Last reviewed .