How many km from Dublin to London?

First off you must take a FERRY from Dublin, Ireland to HOLYHEAD, NORTH Wales, U.K.

Once you are in Holyhead, it is 285 miles (459 kilometres) taking this route:

1. Take A55 BANGOR, from, Holyhead, across to M56 MANCHESTER at J34.
2. Take M56 across to M6(S) to BIRMINGHAM at J9; follow signs on the ramp to M6(S) BIRMINGHAM.
3. Take M6 to M6 TOLL to The SOUTH at J11A.
4. Take M6 TOLL, around BIRMINGHAM to either M6 (S) if you are going to LONDON (N & E) or M42 if you are going to LONDON (S & W).
5. Take M6 to M1 LONDON or take M42 to M40 LONDON.
6. Take M1 or M40 to LONDON.