Watts to Amps Calculator
Convert Watts to Amps with the formula, a worked example and a table of typical values. Working shown step by step.
Try your own numbers
Estimate only. Not engineering or safety advice. Check the result against the applicable standard and the equipment data, and have a competent engineer review it before it is relied on. Terms of use.
Open in the calculator with these values
Formula
Worked example
| Input | Value |
|---|---|
| Power | 2,070 W |
| Voltage | 230 V |
| Power factor | 0.9 |
| Current type | Single-phase AC |
| Voltage type (three-phase only) | Line-to-line (L-L) |
- I = P / (V × pf) = 2,070 / (230 × 0.9) = 10 A
Typical values
| Power (W) | Current (A) |
|---|---|
| 100 | 0.483 |
| 500 | 2.415 |
| 1,000 | 4.831 |
| 2,070 | 10 |
| 3,000 | 14.493 |
| 5,000 | 24.155 |
Other inputs are the same as in the worked example above.
Assumptions
- Single-phase AC by default; choose DC or three-phase above
- V is RMS
- DC takes the power factor as 1
Choose DC to ignore the power factor. For a larger three-phase load the kW to amps calculator also takes efficiency.
Frequently asked questions
How do I convert Watts to Amps?
I = P / (k × V × pf); k = 1 (single-phase, DC), √3 (three-phase L-L) or 3 (three-phase L-N). Worked example: Power 2,070 W, voltage 230 V, power factor 0.9, current type Single-phase AC gives 10 A.
What do I need to enter?
Enter power, voltage, power factor and current type. Change the unit of a value with its selector and the result stays the same.
Does single-phase or three-phase change the answer?
Yes. Pick the circuit type that matches the supply. Three-phase uses √3 with the line-to-line voltage, single-phase uses the voltage as it is, and DC, where it is offered, takes the power factor as 1. The formula above shows each case.
Which power factor should I use?
Read it from the equipment nameplate or data sheet. Typical values are only a guide: about 1.0 for a resistive load and about 0.85 for a fully loaded induction motor. Do not use typical values for accurate work.
How accurate are the results?
Every figure comes from the same tested engine as the Elecmetric calculators and is meant for estimating. Check design values against the standard and the equipment data you work to.
Related
Next steps in a design: Amps to WattskW to Amps
Opposite direction: Amps to Watts
Also see: kVA to Watts Watts to kVA kWh to Watts Watts to kWh
Formula guides: Three-Phase Power FormulasPower Factor and the Power TriangleAC Circuit Formulas: Reactance and Impedance
All 78 conversionsWatts to Amps in Elecmetric