What is an amp symbol?

The symbol used for amperage in formulas is the letter "I", for voltage "E" for watts "W". The formula for watts is W = I x E.

The symbol for electric current is I; the symbol for ampere is A. The symbol for voltage is E, V, or U, depending upon context, and the symbol for volt is V. The symbol for power is P, and the symbol for watt is W.