Watt to Volt-Ampere Converter

A watt (W) is the SI unit of power, defined as one joule per second. Named after Scottish inventor James Watt, it represents the rate of energy transfer and is fundamental to all power measurements in the International System of Units.

The watt was named after James Watt in 1882 and became the SI unit of power in 1960. It replaced various earlier power units and provided a unified measure based on the fundamental relationship between energy and time, becoming universal in scientific and technical applications.

Watts are universally used for all power measurements, from small electronic devices to large machinery. They're fundamental in electrical engineering, physics, energy efficiency ratings, and form the basis for all other power unit measurements.

Volt-ampere (VA) is a unit of apparent power in AC electrical systems, representing the product of voltage and current. It differs from watts (real power) in AC systems where voltage and current may not be in phase.

Volt-ampere became important with the development of AC electrical systems, where the distinction between apparent power and real power became crucial. It provided a way to specify the total power capacity of AC electrical equipment regardless of power factor.

Volt-amperes are used for AC electrical equipment ratings, transformer specifications, and electrical system design. They're standard for UPS ratings, transformer capacity, and AC electrical equipment where apparent power is more relevant than real power.