Why Are Screens Measured Diagonally?

At Electronic World we love everything about our screens; whether that’s being able to assist you in grabbing a bargain or helping you find the perfect TV size for your desired use, we love knowing that we’ve been able to offer your home’s entertainment system that extra edge.

However, one question we often receive when delivering our service is, why are TV screens measured diagonally? It may seem like something of nothing, but now that we’ve asked it, we bet you’re wondering the same! Well, wonder no longer, as we provide you with something of an Electronic World History lesson.

From the TVs of Yore

Way back when our flash cheap 40 inch TVs were but a glint in the internet’s eye, there was such a thing as a Cathode Ray Tube television (ask your great-great-great granddad).

The first of these CRT TVs had a circular picture and, as such, it made sense to explain the size of the screen using the diameter of the image. However as time went on, these circular pictures became rectangular, with the rectangle images touching the edge of this circle.

So, what started as a diameter measurement then became a diagonal measurement from corner to corner. Essentially, the old style of measuring stuck!

A Technology Steeped in Tradition

So what may now seem somewhat silly is actually rooted in logic! However, you may be asking, why not change it? Why not use the length and width measurements of the screen size?

Well, if we were to say to you, “Hey, check out our awesome cheap 42 inch TVs!” You probably have a pretty specific image in your head. Well, how about if we try offer you one of our fantastically bargainous 36.61 inch X 20.59 inch TVs?

…thought not!

Well, they’re actually the same thing. Humans are creatures of habit, so it makes sense to stick with what we know! The crossover period of trying to understand what inch meant what, and which ones still used the ‘old diagonal method’, would be incredibly problematic.

It’s Just Easier!

This may be a little bit of a cop out, but not only is it now a standardised unit of measurement for screens worldwide, it is simply easier to present the size of your screen using only one figure.

Take our cheap 50 inch TVs for example; if we were to start giving you the full dimensions of these screens – length and width – it may start getting a little more confusing… 43.6 inch X 24.5 inch just doesn’t sound as snappy as 50 inch, does it? The same is true of our cheap 43 inch TVs, our cheap 55 inch TVs, our cheap 60 inch TVs and our cheap 65 inch TVs, just to name a few.

Standardised Aspect Ratio

Understandably, with all the new technological developments with televisions, you may think that you would eventually need to offer both length and width. Well, fortunately, the aspect ratio of television screens tends to be consistent. While older TVs were mainly 4:3 – at a ratio of 1.33:1 – most HD TVs these days are part of the 16:9 ratio-crew, meaning there is a fairly consistent aspect ratio of 1.77:1.

If the standard aspect ratio was inconsistent, not only would it make broadcasting more difficult – with channels having to consider significantly different screen sizes (for example, our cheap 49 inch TVs are larger than our cheap 32 inch TVs) – it would throw the traditional method of diagonal screen measurement up in the air.

Thankfully, this level of standardisation makes it easier for everybody, from TV broadcasters to manufacturers to customers like you!

Need Help With Your Purchase?

While we have the team of experts available to contact should you need to ask any questions relating to your purchase, we think this diagonal screen measurement makes understanding your TV significantly easier. You can also learn more about how to measure curved screens if you’re interested in cheap curved TVs.

So next time you hear someone cynically bad mouthing this good ol’ method of denoting TV screen size… you make sure to put them in their place!

Long live the diagonal measurement!