Calculate Electric Power

Analogous to power, electrical power is the energy that is converted per unit time. With direct current, electrical power can also be calculated as the product of voltage and current. The formulas for these two types of power calculation are: electric power = voltage * amperage
P = U * I

power = energy / time, or energy = power * time
P = E / t, E = P * t

Example: the sockets in Germany have a voltage of 230 volts and a nominal current of 16 amps. This means that a maximum power or apparent power of 3680 watts is possible, which is almost 3.7 kilowatts. However, alternating current flows here, which somewhat reduces the effective power, i.e. the power that can also be effectively used. Calculating this effective power is very complicated.

The unit of power is the watt, the unit of voltage is the volt and the unit of current is the ampere. If, for example, a kilo- is placed in front of the unit for voltage or current, i.e. kilovolt and ampere or volt and kiloampere, then the power is in kilowatts. The kilo- means an increase by a factor of 1000. If, on the other hand, the units are kilovolt and kiloampere, then the result is in megawatts, since the voltage is then multiplied by 1000 and the current is multiplied by 1000, i.e. the power is multiplied by a million. Occasionally you will come across the term volt-ampere, which is mostly used for apparent power.
Energy is given in joules, time in seconds. One joule is one watt-second, one watt-hour is 3600 watt-seconds and one kilowatt-hour is 3.6 million joules. In this case, the calculation with the different units is more complicated, since time of course has not only seconds, but also minutes, hours and so on. For a calculation that takes the different units into account, see the Calculator for Power and Energy.