Measure the wall, not the floor

A 3x4 meter room is large enough that the wall matters more than the floor. Measure the clear wall between furniture edges, not the room corners. A print that fills the whole wall will look right from the sofa and wrong from the door. Start with a width that leaves at least 30 centimeters of bare wall on each side of the image. That margin keeps the print from feeling pinned to the plaster. The height follows the composition. A long horizontal scene needs width first. A vertical one can sit higher on the wall without losing its presence.

The anxiety here is real. A print that is too small disappears at sitting distance. A print that is too large makes the room feel smaller than it is. The middle ground is usually the right one for a living room, because people look at the wall from several points in the room, not from one spot. If you can only hang one piece, give it room to breathe. If you plan a group of smaller works, treat the group as one unit and size the whole arrangement to the wall.

Match the print to the furniture below it

Furniture sets the lower edge of the composition and often the visual weight of the whole wall. A sofa that is two meters wide can carry a print around 1.2 meters wide without looking crowded. A low console or a bare wall can take a taller image. The print should not float above a sofa with a gap that reads as an accident. Keep the bottom of the frame roughly level with the top of the backrest, or a little higher if the ceiling is high. That is a starting point, not a rule, because the room may have other things on the wall.

A Cyril Power reproduction is usually a city scene or a railway subject, and those compositions tend to run horizontally. That shape works well above a sofa because it mirrors the width of the furniture. It works less well on a narrow wall between two doors. If you are deciding between two sizes, hang a paper mockup at both scales before you commit. Tape the outlines on the wall and stand where you sit. The right size is the one that reads clearly from the sofa without making the wall feel occupied by something heavier than the room.

Scale the print to how the room is used

A living room is used at different distances, and that changes what size reads well. A print seen from a sofa needs enough detail to hold attention at one and a half meters. A print seen from a doorway needs enough scale to register across the room. If the room is mostly for sitting and conversation, size for the sofa view. If people pass through it often, give the print enough width to be noticed from the entry. Neither choice is wrong. They are different rooms in the same square meters.

Price sensitivity makes this harder, because a larger print costs more and a smaller one feels safer. The safer choice is not always the better one. A print that is too small will be replaced sooner, because it never quite fits the wall. A print that is well sized on the first try costs less in the long run than a second purchase. If you are unsure, choose the size that fits the main wall and the main view, then live with the mockup for a day. The room will tell you whether the print is too quiet or too loud.