📺 TV Size Calculator
Find your TV’s exact width, height, and screen area, plus the recommended viewing distance, from its diagonal size.
How TV dimensions are calculated
TVs are advertised by their diagonal screen measurement, but the actual width and height depend on the screen’s aspect ratio. This calculator uses the Pythagorean theorem to split the diagonal into its width and height components based on your chosen aspect ratio.
Formula used: for an aspect ratio W:H, Height = Diagonal ÷ √(ratio² + 1) and Width = Height × ratio, where ratio is width divided by height (for example, 16:9 = 1.778).
- 16:9 is standard for modern HDTVs and streaming content.
- 21:9 is common for ultrawide monitors and some cinematic content.
- 4:3 was the standard for older analog televisions.
The recommended viewing distance range uses a common home-theater guideline of roughly 1.2 to 1.8 times the screen diagonal (in inches), converted to feet, for comfortable viewing of HD and 4K content. This tool is for general reference and planning purposes.