Why a 65-inch screen is not 65 inches wide
The number on the box is the diagonal, corner to corner. The width follows from the shape: on a 16:9 panel the diagonal is 2.04 times the height, so 65 inches of diagonal leaves 31.87 inches of height and 56.65 inches of width. That is why a set sold as 65 inches measures a bit under 57 inches across the glass.
Change the shape and the same diagonal spreads differently. A 65-inch 21:9 panel is 59.74 inches wide but only 25.60 inches tall — about 3 inches wider and 6 inches shorter than the 16:9 version. Same number on the box, different piece of wall.
Width and height by size
These are the 16:9 figures for the sizes sold most often. Bezel and stand are not included, so a real set is a little wider than the number here.
| Diagonal | Width | Height | Area |
|---|---|---|---|
| 43 in | 37.48 in / 95.2 cm | 21.08 in / 53.5 cm | 790 sq in |
| 50 in | 43.58 in / 110.7 cm | 24.51 in / 62.3 cm | 1,068 sq in |
| 55 in | 47.94 in / 121.8 cm | 26.96 in / 68.5 cm | 1,293 sq in |
| 65 in | 56.65 in / 143.9 cm | 31.87 in / 80.9 cm | 1,805 sq in |
| 75 in | 65.37 in / 166.0 cm | 36.77 in / 93.4 cm | 2,404 sq in |
| 85 in | 74.08 in / 188.2 cm | 41.67 in / 105.8 cm | 3,087 sq in |
How the numbers are calculated
Everything comes from the diagonal and the ratio, so nothing is looked up:
height = diagonal ÷ √((a ÷ b)² + 1)
width = (a ÷ b) × height
area = width × height
centimetres = inches × 2.54
square centimetres = square inches × 6.4516
diagonal in pixels = √(pixels wide² + pixels high²)
PPI = diagonal in pixels ÷ diagonal in inches
The ratio a:b is the width over the height, so 16:9 means 16 units across for every 9 down. The pixel rows only run when a resolution is chosen; they do not change the width, the height or the area.
What is rounded
Width and height are shown to 2 decimals in inches and 1 decimal in centimetres, area to the nearest square inch with a thousands separator, and the centimetre area to the nearest square centimetre. PPI is shown to 1 decimal. The arithmetic runs at full precision and only the display is rounded, so a difference that reads as 0.00 at the shown precision is still a real difference in the panel.
What is measured
These are the active panel measurements: the lit rectangle you watch. Bezels, the frame around the glass, the stand and the depth of the chassis are all excluded, so a 65-inch set will measure wider than 56.65 inches once you include the frame — usually by half an inch to an inch and a half. Wall space is the width figure, because the panel is mounted flat; add clearance for the mount if it tilts. Where to put the seat is a different question, and that one is worked out here.
Comparing two sizes instead of reading one: 55 vs 65 inch tv keeps both panels editable and shows the width, height and area difference in inches and percent. Monitors use the same geometry, and monitor dimensions calculator adds pixel pitch and area to it. The 55 inch figures on their own — width, height, height with stand — are on 55 inch tv dimensions.
Questions this page answers
So how wide is a 65-inch TV really?
56.65 inches across the glass, or 143.9 cm, for a 16:9 panel. The 65 is the diagonal, not the width.
And how tall is it?
31.87 inches, or 80.9 cm, at 16:9. A 21:9 set of the same diagonal is wider but shorter: 59.74 in across and 25.60 in tall.
How much wall does one take up?
As much as the width, 56.65 inches, plus whatever the frame adds on each side. Height matters for the mount position rather than the wall width.
Do these numbers include the frame around the screen?
No. They are the lit panel only. Real sets add roughly half an inch to an inch and a half across, and a stand adds depth at the bottom.
What if I'm looking at the 55-inch version?
Type 55 in the diagonal box. A 55-inch 16:9 panel is 47.94 in wide and 26.96 in tall, so it is about 8.7 inches narrower than the 65.
Why does my tape measure disagree with the spec sheet?
Usually the frame, or measuring a curved set along the curve instead of across the flat. The panel figure here is the flat rectangle inside the bezel.