General discussion

how is an LCD screen measured?

in the "good old days" a tube TV was measured diagonally (and you usually lost a portion due to the box the tube sat in)

is an LCD measured the same way?, and if so, how is a "wide screen" -16:9- LCD measured?



Discussion is locked

Reply to: how is an LCD screen measured?
PLEASE NOTE: Do not post advertisements, offensive materials, profanity, or personal attacks. Please remember to be considerate of other members. If you are new to the CNET Forums, please read our CNET Forums FAQ. All submitted content is subject to our Terms of Use.
Reporting: how is an LCD screen measured?
This post has been flagged and will be reviewed by our staff. Thank you for helping us maintain CNET's great community.
Sorry, there was a problem flagging this post. Please try again now or at a later time.
If you believe this post is offensive or violates the CNET Forums' Usage policies, you can report it below (this will not automatically remove the post). Once reported, our moderators will be notified and the post will be reviewed.
- Collapse -
Here is an interesting site
- Collapse -
Not easy to answer.

In the "good old Days" it was the diagonal of the visible part of the tube. CRT PC monitors things changes sightly, most said 17" CRT with 16" visible. But for LCD it should just the visible diagonal of the screen. John

- Collapse -

all TV screens are measured diagonally. now if a manufacturer makes their "32in tv" ACTUALLY 32in is hit and miss. if you have a space constraint, whether it is the screen size, or the total size of the TV you should bring your own tape measure.

- Collapse -
(NT) thanks for the help y'all :)
- Collapse -
Diagonal measure sells better

All TVs and monitors are measured by the diagonal size of the actual glass front of the screen
With old TVs and monitors part of that measured screen is hidden by the chassis.
With LCD the method in which the screen is mounted on the chassis allows more of the full screen to be visible.
The reason for the diagonal measurement goes back to 1966 when the Fed register in USA ratified that the method was acceptable. Read the reason for that decision at
As for the 16:9. Old TVs had a ration of 4:3 or 4 units wide and 3 units high. 16:9 was chosen because contained full numbers. Sounds better than 4:2.25

- Collapse -
16:9 was chosen because contained full numbers.

What the heck are you talking about?

4:3 is the aspect ratio defined by the Academy of Motion Picture Arts and Sciences as a standard after the advent of optical sound-on-film. By having TV match this aspect ratio, films previously photographed on film could be satisfactorily viewed on TV in the early days of the medium (i.e. the '40's and the '50's). When cinema attendance dropped, Hollywood created widescreen aspect ratios (such as the 1.85:1 ratio mentioned earlier) in order to differentiate their industry from the TV.

16:9 is the international standard format of HDTV as used in Australia, Japan, Canada, and the United States, as well as in Europe on satellite and non-HD widescreen television (EDTV) PAL-plus.

There are still a couple of different ratio widescreen - letterbox for instance. Used in movie production. 16:9 is the new TV standard. 4:3 is destined for the trash heap. None to soon either...

- Collapse -


- Collapse -
LCDs are measured diagonally

LCDs are measured diagonally, regardless of aspect ratio. But it's different from a picture tube's diagonal measurement.

An LCD is measured diagonally from diagonally opposite extreme corner pixels. It's a very straightforward measurement.

CRTs (picture tubes, in monitors or TV sets) are also measured diagonally, but it's the GLASS, not the picture, that is measured. So the measurement is larger than the diagonal measurement of the largest possible image, often by about 2 inches. Consequently, a 17" LCD has about the same image size as a 19" CRT. Since the thickness of the glass and the useable image area can vary, two picture tubes of the same size may have slightly different maximum image sizes. And picture tubes also "underscan", so the image size actually seen is usually smaller than the maximum possible image size even on the same tube.

CNET Forums

Forum Info