How to measure your wall.
When measuring your wall, always double check, then triple check.
Walls are rarely absolutely square, so measure the height of both ends (1)&(3) and the middle (2) and use the largest measurement. Do same for the width.
The size you give us will be the size your wall covering arrives plus 50mm we add to the height and width of your mural. You'll trim off any excess once fixed to the wall.
Ignore any electrical sockets, doors, windows etc. Simply cut around these when putting up the wall covering.