Manx Utilities has published guidance around specific running costs for items in the home, using electricity prices that will apply until 31 March 2023.
On one hand, some stuff is unintuitively cheap in their usage of electricity: a full charge of your mobile phone probably costs around 1p. On the other hand, towel rails are very expensive: if it uses 200 watts, that is likely to be over £1/day. I’ve just turned mine off!
See below for their (current) estimates on the cost of various appliances.