Current = Power (watts) / Voltage

A standard ring main is 30amps but each socket (double or single) can't be loaded with more than 13amps as standard mains power cable is only rated at 18.5 amps if it is installed in a wall. This gives the ring main a rated current carrying capacity of 37amps but dont forget it will trip when you load it above 30amps.

You can get different types of trips for home use. Some will not trip with sudden power demands (i believe its type c but i would check it online first).

Hope that makes sense