Measuring your wall for a TV
"Will a 75 fit?" is a question about width, and TV sizes are diagonals. Ten minutes with a tape measure before buying prevents the two classic problems: a screen that overhangs the fireplace, and a screen that looks lost on a big wall.
Diagonal to real size
For standard 16:9 TVs, the screen's width is about 87% of the diagonal and the height about 49%. Add roughly an inch each way for the frame.
| Size | Approx. width | Approx. height |
|---|---|---|
| 43″ | 38″ | 22″ |
| 50″ | 44″ | 25″ |
| 55″ | 48″ | 28″ |
| 65″ | 57″ | 33″ |
| 75″ | 66″ | 38″ |
| 85″ | 75″ | 43″ |
| 98″ | 86″ | 49″ |
Exact figures for each size are on our TV size pages. For a specific model, use the dimensions "without stand" in its specifications.
Measure the space
- Available width between whatever bounds the TV: windows, door frames, corners, built-ins, the edges of a fireplace surround.
- Available height between the mantel, console or baseboard and the ceiling, crown moulding or a shelf.
- Obstacles inside that rectangle: light switches, thermostats, outlets, vents, sconces.
Leave breathing room
A TV that touches both sides of its space looks jammed in.
- Aim for at least 3 to 4 inches of wall on each side; more looks better.
- Over a fireplace, the TV should be no wider than the mantel, and ideally a little narrower than the firebox surround.
- Above furniture, the console should be wider than the TV; see TV above a console.
- Leave 4 to 8 inches between the bottom of the TV and the mantel or console top.
Check the viewing distance
Measure from the wall to where your eyes will be. As a rough guide for 4K TVs, a comfortable screen diagonal is about the distance in inches divided by 1.5 to 2.0 — at 10 feet (120 inches), that's roughly 60 to 80 inches. Details in the viewing distance guide and what size TV for my room.
Mock it up
Cut the TV's outline from cardboard or mark it with painter's tape at the planned height. Then:
- sit in every seat and check the angle,
- look at it from the doorway,
- check for window reflections at different times of day,
- leave it up overnight.
This costs nothing and settles most arguments about size.
Things people forget to measure
- Swing room for a full-motion mount: an extended, angled TV needs clear space beside it.
- The path into the room. An 85-inch box is about 7 feet long; check stairs and corners.
- Depth, if the TV sits in a niche.
- Stud locations, so you know whether the bracket can be centred — see finding studs.
- Outlet position relative to the TV's outline.
Bring the numbers
When you book, put the wall type and anything unusual in the notes. On our planner you can drag the size slider and see the TV drawn to scale on a wall with a person for reference.