Borrow a meter

It is worth borrowing an electricity consumption meter when your electricity consumption has unexpectedly risen or seems considerably high. The meter is easy to use and it can be borrowed for one week at a time. Consumption meters can be used for measuring appliances that are plugged into the mains socket. Therefore, they are not suitable for measuring the consumption of a cooker or sauna.  

Consumption meters can reveal the energy gluttons of your home. For example, you may have left the fast-freeze button of a refrigerating appliance on for a long time. Many matters that may seem trivial can increase electricity consumption. Keeping the television in standby mode alone costs about 7 euros per year. A new appliance with low power consumption can consume twice as much electricity if its ventilation is blocked.

The electricity consumption of new appliances is given as average figures. The amount of energy consumed is affected by, e.g. the power of the appliance, the length of use, thermostat controls, method of use, location, and maintenance. 

Take a look here, how much domestic appliances use electricity and how much it costs.