What is a current of transformers?

The current rating of transformers vary widely as well as the types (step-down, etc.....). So depending on the use, the primary power, and the secondary power, the amp load will change. More in general current is amps, if your transformer has say 1Kva on it then that tells you the apparent power the transformer can handle. As a side note a lot of transformers are rated in VA or KVA and that is a combination of volts and amps (apparent power).