Ofcom has created an online tool that lets people see what kind of mobile coverage they should be getting.

The coverage map is based on data provided by mobile operators as well as Ofcom's own testing of signal strengths around the UK.

The webpage has gathered data about the quality of voice calls as well as 3G and 4G data.

The watchdog said it was seeking feedback to fine tune the map to make it more accurate.

"Access to reliable mobile phone coverage used to be a 'nice to have'," said Steve Unger, Ofcom's chief technology officer in a statement. "Now it's essential to many people's lives."

The map-based system can be searched via postcodes, or visitors to the page can simply zoom in to a location.

Coverage strength is given for both indoors and outdoors. In addition, the map provides information about geographic features, such as valleys or hills, that might mean signal strengths are lower than expected.

Ofcom said the coverage the map showed might not be the same as that seen on operators' websites because it amalgamated data from phone firms - each one of which used slightly different methods of measuring signal strength.

If a phone was being used in a busy area this might also affect a person's experience as congestion might limit data rates to an individual handset.

Ofcom added signal strength and available services can be changed by the handset that someone uses.

If people were getting very a different service to that seen on the map, Ofcom said people should provide feedback so the data can be updated.