Single-Phase Power Calculator (V, A, W, kW)
Calculate single-phase electrical power using P = V × I. Solve for watts, amps, or volts and convert to kW for HVAC field work.
This calculator is part of the HVACTools.pro free calculator collection, built for working HVAC technicians. The interactive widget loads when the page hydrates; the content below previews related tools while it loads.
Frequently asked questions
What is the single-phase power formula?
For basic single-phase DC or resistive loads, power in watts is P = V × I (volts times amps).
How do I convert watts to kilowatts?
Kilowatts are watts divided by 1000. Example: 4500 W = 4.5 kW.
Does this handle power factor?
This tool uses the basic P = V × I relationship. For inductive loads (motors), true real power may be lower due to power factor. Use measured watts, or include PF separately when doing design-level calculations.
When is this useful in HVAC work?
It helps estimate electric heat strip kW, compare expected blower/control loads, and sanity-check amperage vs nameplate power on single-phase equipment.
Related calculators
Browse all HVAC calculators · Troubleshooting workflows · HVAC guides · Tool reviews