Power measures the rate at which energy is transferred or work is done. The SI unit is the watt, equal to one joule per second. Power units appear in motors, engines, pumps, compressors, generators, appliances, HVAC equipment, electrical systems, and energy analysis.
What power units measure
Power measures the rate at which energy is transferred or work is done. The SI unit is the watt, equal to one joule per second. A good unit reference should preserve the original unit, explain the conversion relationship, and show when a rounded value is only a display convenience.
Unit scale and relationships
The chart below compares each unit against the base unit used by Xunits for power conversions.
Common use cases
Power units appear in motors, engines, pumps, compressors, generators, appliances, HVAC equipment, electrical systems, and energy analysis. In these workflows, the right unit is usually the one used by the instrument, source document, regulation, buyer, or local convention.
Common mistakes
- Do not confuse power with energy. Kilowatt is power; kilowatt-hour is energy accumulated over time.
- Do not copy a number without its unit symbol; the same number can mean very different things in another unit.
- Do not round intermediate values when the converted result will be reused in a formula, specification, or limit check.
Available power unit guides
Each guide explains one unit in depth, then links back to the most useful converter pages.
Related converters
Use converter pages when you need a direct numerical answer.