A gallery wall should be measured as one complete composition. The outer dimensions of every frame, every gap, and the relationship to nearby furniture determine whether it fits the room.
Record true outside dimensions
Frame labels usually describe the photograph, not the finished object. Measure or confirm the full exterior width and height of each frame, including irregular borders or mats, before calculating the layout.
Build the total width and height
Add frame widths across each row plus every horizontal gap. Do the same vertically for rows and gaps. Use the widest row and tallest column as the minimum bounding box, then compare it with the clear wall area.
Relate the gallery to the room
Check the composition against furniture, switches, vents, shelves, doors, and sightlines. A centered gallery may align with the sofa, bed, or console below rather than the entire wall.
Test with paper templates
Cut paper to each frame's outside size, label it, and place the full arrangement with removable tape that is safe for the finish. This makes spacing, scale, and visual balance easier to judge before holes are made.
Map every hanging point
The hook location may sit well below the frame's top edge and can vary between frames. Measure the hardware under tension, transfer each point carefully, and use mounting methods suitable for the wall and frame weight.