There are several ways to get the best viewing distance: you might browse Google for instance, visit avforums.com and ask a question – or you can quickly work it out for yourself with a tape measure (which you would need in any case to measure the distance from your display to your sofa or chair).

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While you could extrapolate these guidelines for a widescreen 16:9 ratio TV:
- 28-32" - viewing distance 2.5-3m
- 36-42" - viewing distance 3-4m
...these only apply to widescreen TVs – 4:3 ratio displays require a slightly different viewing distance.
However, it is a very simple method to calculate the optimum viewing distance on LCD TVs – all you need to do is multiply the diagonal dimension of your TV set.
The diagonal dimension is the accepted display size as detailed in the device literature and advertising – as such for a device with a 32” display, you should be looking to position your seating 8 feet from the source (based on 32 x 3 = 96, 96 divided by 12 = 8).
Using this rule of thumb you can suitably position your seating at the optimum range from any TV regardless of its size, ratio or display type.