Watts and amps are both measurements that involve the consumption of electricity, and they measure two different things. A watt is a measurement of power conversion, whereas amps measure the amount of electricity passing a point in a given amount of time. They can be converted, but only if you also know the voltage.
1 – Determine the voltage. You can do the math if you know either watts or amps, but you need the voltage to do it. North American wall outlets operate at 110 volts, whereas those in Europe vary from 210 to 240.
2 – Use a calculator, or a pen and paper if you do not have one.
3 – Convert watts to amps using this equation: amps = watts divided by volts. An example is that a typical 60 watt light bulb on the standard 110 U.S. voltage operates at 0.54 amps (60/110 = amps). The same bulb on European voltage is .025 amps (60/240 = amps).
4 – Convert amps to watts by reversing the equation: amps multiplied by volts = watts. A device operating on 3 amps at 110 volts consumes 330 watts (3 x 110 = watts).