PowerTotals

Power & phase

Single-Phase Power Calculator

Single-phase apparent power equals voltage multiplied by current. Real power is apparent power multiplied by power factor.

Calculate real power, apparent power, and current for a single-phase AC circuit.

Enter values

Advanced assumptions

Calculated result

Single-phase power result

Calculating…

Calculated locally in your browser

Planning math only. Verify equipment specifications and installation requirements separately.

Single-phase power relationship diagramAn original simplified phase diagram paired with the current calculator result.V · I · PF · PHASERESULTCalculated locallyFORMULA VISIBLEINPUTS EDITABLE
Single-Phase Power Calculator relationship diagram. The illustration supports the text result; it is not a wiring or installation drawing.

What this calculator returns

The result keeps real and apparent power separate so the PF assumption remains visible.

Formula and variables

The calculation runs entirely in your browser. Static formulas, definitions, examples, and tables remain readable without JavaScript.

Formula

S = V × I; P = V × I × PF.

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.

S is apparent power in VA and P is real power in W.

Worked example

Worked example inputs and result
InputValue
Voltage240 V
Current10 A
Result240 V × 10 A × PF 0.8 = 1.92 kW and 2.4 kVA.

240 V × 10 A × PF 0.8 = 1.92 kW and 2.4 kVA.

Reference table

Phase relationships derived from the steady-state real and apparent power equations used by these calculators.
SystemApparent powerReal powerVoltage entry
DCS = V × IP = V × ICircuit voltage
Single-phase ACS = V × IP = V × I × PFRMS circuit voltage
Balanced three-phase ACS = √3 × VLL × IP = √3 × VLL × I × PFLine-to-line RMS voltage

Frequently asked questions

Is this single-phase power 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.

Assumptions and limitations

  • Steady-state sinusoidal planning model.
  • No branch-circuit or protection sizing.

Method and sources

Read the calculation methodology, review the technical sources, or browse the reference table index. Last reviewed .

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