How are Monitor Screen Sizes Measured These Days?

[BobH]

Back when screens first entered everyone's home - remember the stunning 21" TV? - sizes were measured diagonally from an upper corner to a lower corner (or vice versa). The measurement gave a relative size but did not describe the horizontal or vertical measure of a screen.

Is the same practice followed with today's flat panel LED screens? Is a 24" monitor measured on the diagonal?

[BobArch2]

Back when screens first entered everyone's home - remember the stunning 21" TV? - sizes were measured diagonally from an upper corner to a lower corner (or vice versa). The measurement gave a relative size but did not describe the horizontal or vertical measure of a screen.

Is the same practice followed with today's flat panel LED screens? Is a 24" monitor measured on the diagonal?

YUP.

[HansV]

Bob is correct.

In the good old days, computer monitors almost always had a 4:3 aspect ratio. Pythagoras' law tells us that the sides and diagonal formed a 3-4-5 triangle, so it was easy to compute the width and height of the screen. For example, the screen of a 15" monitor was 12" wide and 9" high.

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Nowadays, most monitors are wide-screen, with aspect ratios such as 16:9 or 16:10. It's a bit more work to compute width and height, but it's still possible.

[Rudi]

Two answers on Yahoo Answers:

ANSWER 1:
All the angles are fixed and you know the ratio of the 2 sides.
That means the ratio of the hypotenuse to the sides is also fixed.
All that remains is to figure out the hypotenuse ratios.

Calculate the hypotenuse for the given ratio:
sqrt(16^2 + 9^2) = H

Then:
height = 9 / H * D
width = 16 / H * D

Note that for TV's, the measurements can be off since they often round the diagonal size.

ANSWER 2:
You use Pythagoras' Theorem for right triangles: c^2 = a^2 + b^2

c is the hypotenuse (the diagonal),
a is the height,
b is the width.

First you need to define the width b, in terms of the height a, which you can since you know their proportion is 16:9.

b = 16a / 9

Plug that into the c^2 = a^2 + b^2 Pythagoras theorem, you get:

c^2 = a^2 + (16a / 9)^2.

Plug in the diagonal c, and you can solve for height a.

Once you get the number for height a, plug it into the b = 16a / 9 equation to solve for width b.

[BobArch2]

Is the same practice followed with today's flat panel LED screens? Is a 24" monitor measured on the diagonal?

Hey BobH,
Hans and Rudi are really complicating a simple answer. Tsk, Tsk. Just grab one of these when you go to the TechShop...

TM.gif

[Rudi]

That would deserve a measured

[BobH]

I have a much smaller pocket sized tape measure that only measures up to 96." I think it will be a little easier to use than that 100-footer.

My question was generated by looking at online adverts and not knowing how to relate the sizes of modern wide screen monitors to the size of my desk.

Thanks for all the help!

I am a bit too obtuse and cannot figure out Rudi's HY-potheses.

[BobArch2]

My question was generated by looking at online adverts and not knowing how to relate the sizes of modern wide screen monitors to the size of my desk.
I am a bit too obtuse and cannot figure out Rudi's HY-potheses.

I'm with you on Rudi's Hy-potheses!
Here's a snap of my work station with a pair of Samsung 24" monitors. The height from the top of the desk to the top of the monitors is about 18.5" which includes the stands. The overall width being 44".

Combo3.gif

[Rudi]

Just 2 B clear, it's SUM-1-Other's-Potheses!
My solution would be to borrow BobH's small pocket sized tape measure.

[PaulB]

Bob, you stated in another thread, "It would appear that our environments are alike."

You have no idea!

Spoiler

IMG_4504.jpg

[Jay Freedman]

If, like BobH, you're looking at adverts and you don't have the monitor in front of you, the tape measure won't do a lot of good (hey, stop trying to measure my waistline!). Instead, here are a few numbers from trigonometry (remember that?)...

If the monitor's resolution is 4:3, the width of the screen is the diagonal size multiplied by 0.8.
If it's a widescreen 16:10, the multiplier is 0.85.
If it's a widescreen 16:9, the multiplier is 0.87.

None of these numbers include the width of the bezel, which can vary considerably.

[Rudi]

LOL... I love this game: Spot the difference.
Let's play....

[viking33]

Funny, I recently had a discussion with a friend, who wanted to know if all desktop computer systems were required to have that awful jungle of wires and cables behind the monitor and tower, etc?
I said that while not required, the amount of cabling and twisted wires were an indication of the relative changes made over time. More cables, more speed and up to date hardware. ( besides, the spiders loved to make their homes in there )
She said, thanks, I always wondered about that!

[stuck]

ooking at online adverts and not knowing how to relate the sizes of modern wide screen monitors to the size of my desk

Ah! If that's the real problem you've got then you don't need maths of a tape measure because if the ad. you are looking at doesn't give anything more than the diagonal then simply Google the model number and find the full specs from somewhere else, e.g the manufacturer's site or somewhere like Amazon. The full specs will give the actual width and height, plus a load more stuff you probably don't need to know.

Ken

[BobH]

Good suggestion.

Thanks, Ken.

And further congratulations to you and s2.

[jonwallace]

Funny, I recently had a discussion with a friend, who wanted to know if all desktop computer systems were required to have that awful jungle of wires and cables behind the monitor and tower, etc?
I said that while not required, the amount of cabling and twisted wires were an indication of the relative changes made over time. More cables, more speed and up to date hardware. ( besides, the spiders loved to make their homes in there )
She said, thanks, I always wondered about that!

You're not wrong Bob. When I got a new desk recently, I discovered that I've been too lazy to untangle the wires of defunct equipment, I just unplugged the power brick and dropped it down the back (sometimes I had forgotten to unplug the brick as well...) My junk cable box now has two "spare" power bricks and a network cable...