The Aspect Ratio of a video/television image is the ratio of its width to its height.
Traditionally, televisions have had an aspect ratio of 4:3, ie a screen width proportion of 4 to a screen height of 3. For every unit change in height there is a corresponding change in width of 1.33 (4/3). This shape gives the appearance of a square-like box.
More recent televisions - wide screen - for the most part, have an aspect ratio of 16:9. This shape moves towards a more elongated form similar to that experienced in the cinema. The change in width is now 1.78 (16/9) units of measurement to every unit change in height.
The size of a television is usually described in diagonal inches. Inch size refers to the length of the diagonal.
The diagonal is the distance from the top left corner of the visible screen to the bottom right corner. Alternatively, this can be the distance from top right to the bottom left corner.
A television with a 4:3 Aspect Ratio will always have a larger viewing area than one with a 16:9 Aspect Ratio for the same diagonal size.
You can see displayed a diagram of a 4:3 Aspect Ratio and a 16:9 Aspect Ratio. Seeing is believing!
The Aspect Ratio calculator, among other purposes, can be used to resize a photo while retaining the original aspect ratio ie the original width to height proportion.
Below select an aspect ratio of 4:3, 16:9 or input ANY width/height ratio in which you may be interested.
Input the width, height or diagonal.
You can also calculate to any decimal places you want to.