Linear voltage regulator question

Take for example I regulate 5V from a 12V battery. The device draws 20mA. Will the total power be 12 x 0.02 or 5 x 0.02 watts?

The power dissipated at the load will be .020 * 5 = 0.1 watt. The power dissipated by the regulator will be 12 - 5 = 7 volts * .020 amp = 0.14 watt. Total power will be 0.1 watt + 0.14 watt = 0.24 watt. This is the same as 12 volts * .020 amp = 0.240 watt which is the total power. The load dissipates some and the regulator dissipates some.

Ron