Current
Estimate line current from real power, voltage, phase, and power factor.
Load current
10.613 A
Apparent power
8.824 kVA
Formula
I = kW * 1000 / (sqrt(3) * VLL * PF)
Calculators
Calculator
Free 3-Phase Current Calculator: kW to Amps
Calculate three-phase line current from real power, line-to-line voltage, and power factor. The same free tool also switches to single phase for loads supplied by one AC voltage.
Free complete single- and three-phase calculator — no account required
Balanced-load formula
3-phase current calculator formula
I = (kW × 1,000) ÷ (√3 × VLL × PF)
To convert three-phase kW to amps, use total real power, line-to-line voltage, and power factor for a balanced load. The calculator handles the unit conversion and also supports single-phase estimates.
Worked comparison: 30 kW at 0.90 power factor
Holding power and power factor constant shows why the same load draws less current at a higher voltage.
| Line voltage | Calculation | Estimated line current |
|---|---|---|
| 208 V | 30,000 ÷ (1.732 × 208 × 0.90) | 92.5 A |
| 240 V | 30,000 ÷ (1.732 × 240 × 0.90) | 80.2 A |
| 480 V | 30,000 ÷ (1.732 × 480 × 0.90) | 40.1 A |
Single-phase formula
Convert single-phase kW to current
I = (kW x 1,000) / (V x PF)
Use the voltage across the single-phase load. Power factor belongs in the denominator when the entered kW is real power. For a resistive unity-power-factor load, use 1.00.
Worked single-phase current examples
These examples show how voltage and power factor change current for common 120 V and 240 V loads.
| Load | Power factor | Calculation | Estimated current |
|---|---|---|---|
| 1 kW at 120 V | 1.00 | 1,000 / (120 x 1.00) | 8.33 A |
| 2 kW at 120 V | 0.90 | 2,000 / (120 x 0.90) | 18.52 A |
| 5 kW at 240 V | 0.90 | 5,000 / (240 x 0.90) | 23.15 A |
Check the inputs before using the result
- Use the load's line-to-line voltage for the balanced three-phase formula.
- For single phase, use the actual voltage across the load and do not add the square-root-of-three factor.
- Enter real power in kW and power factor as a decimal, such as 0.90 rather than 90.
- Treat the result as a balanced steady-state estimate; starting, harmonic, and unbalanced loads need a different review.
- Compare the estimate with equipment nameplate data and measured phase currents before acting on it.
From estimate to field-ready work
Use the free answer, then choose the depth you need
The calculator stays free for quick current estimates. Toolkit adds motor, transformer, voltage-drop, wire, and protection review tools. Pro Toolkit adds complete troubleshooting guides and browser-local field records with PDF output.
Free three-phase reference
Review the public diagram, voltage table, cautions, and common questions.
Open referenceToolkit electrical workbench
Continue into editable motor, power, transformer, voltage-drop, and protection workflows.
Preview ToolkitPro field records
Build repeatable commissioning, incident, change, backup, and handoff records.
Preview Pro workflowsNeed more than the free current estimate?
Toolkit is $5/month for advanced electrical tools. Pro Toolkit is $15/month and adds troubleshooting procedures, field records, and included library downloads. This current calculator stays free.
Estimate boundary
This calculator estimates steady-state current from kW and power factor. Use equipment nameplate values and applicable motor, conductor, and protection requirements for final design decisions.
Supporting knowledge-base guides
Start with a public worked example, then use the complete Pro procedure for commissioning and troubleshooting.
Single-phase current guideWork the kW, voltage, and power-factor formula with a 120 V example and common input checks.Three-phase power topic hubPublic formula map, voltage comparison, FAQs, and supporting guides.208, 240, and 480 V examplesCompare current at common line-to-line voltages with consistent assumptions.Motor-current estimatesInclude horsepower, efficiency, and power factor without treating estimates as nameplate data.Power-factor cautionsRelate kW, kVA, kvar, and current while preserving the load basis.Common formula mistakesCatch missing square-root-of-three, unit, and efficiency errors.