# Aspect ratio / scrren size calculator

Discussion in 'Displays' started by Father John A, Dec 19, 2004.

1. ### Father John A Stunt Coordinator

Joined:
Jul 22, 2002
Messages:
146
0
Trophy Points:
0
Anyone know of a calculator that will give relative picture area depending on screen size and aspect ratio?

i.e.: If I had a 50" and was watching LOTR 2.35:1, what would the pciture size be?

2. ### Mark Larson Supporting Actor

Joined:
Mar 3, 2002
Messages:
537
0
Trophy Points:
0
50²=(16x)²+(9x)²
2500=256x²+81x²
337x²=2500
x²=2500/337
x²=7.42
x=2.724

16x=43.6"

3. ### Father John A Stunt Coordinator

Joined:
Jul 22, 2002
Messages:
146
0
Trophy Points:
0
You completely lost me.

Thanks though.

4. ### ScottHH Stunt Coordinator

Joined:
Oct 24, 2002
Messages:
174
0
Trophy Points:
0
There is at least one Calculator on the internet to do it for you, but Mark showed you the math behind the calculators (aka The Pythagorean Theorem a²+b²=c²).

Assume this is the TV.

We know the ratio of the height and width of all TVs:
If it's a 16:9 TV, height a=9x and width b=16x
If it's a 4:3 TV, height a=3x and width b=4x

Here's the diagonal of the TV:

Now we can substitute x for a and b in Pythagorean Theorem:
If we assume your 50" TV is a 16:9 widescreen set, we get:
(9x)²+(16x)²=50²

Mark then solves this equation for x (a little algebra), and calculates x=2.724

So a 50" diagonal 16:9 has the following dimensions:
16x=43.6"