Any website that gives you an exact figure is probably incorrect. We all have different living conditions, different sized houses, modern houses, old houses, different lifestyles and habits, and different tariffs from different utility providers, so we’ll all have different costs.
It’s really impossible to give hard and fast figures. However, we can compare the energy usage of various electrical items so that you can get an idea of which appliances use the most and where to focus your efforts. You can also compare with your own tariff as quoted on your energy bill to calculate how much you stand to save.
FYI: What is a kilowatt hour (KWh)? This is the amount of energy you’d use if you kept a 1 kilowatt appliance running for one hour.