The volt-ampere (SI symbol: VA,[1] sometimes V⋅A or V A) is the unit of measurement for apparent power in an electrical circuit.

In direct current (DC) circuits, this product is equal to the real power, measured in watts.

[3] The volt-ampere is dimensionally equivalent to the watt: in SI units, 1 V⋅A = 1 W. VA rating is most used for generators and transformers, and other power handling equipment, where loads may be reactive (inductive or capacitive).

The term var was proposed by the Romanian electrical engineer Constantin Budeanu and introduced in 1930 by the IEC in Stockholm, which has adopted it as the unit for reactive power.

Special instruments called varmeters are available to measure the reactive power in a circuit.