TV Size Converter
Convert TV screen diagonal to width and height in inches and cm.
Covers 16:9, 4:3, and 21:9 aspect ratios for TVs, monitors, and projector screen sizing.
Enter the diagonal size — see width and height dimensions.
TV size is measured diagonally across the screen.
For standard 16:9 TVs:
- Width = Diagonal x 0.8716
- Height = Diagonal x 0.4903
For ultrawide 21:9 screens:
- Width = Diagonal x 0.9097
- Height = Diagonal x 0.3899
Common TV sizes (16:9):
| Diagonal | Width (in) | Height (in) | Width (cm) | Height (cm) |
|---|---|---|---|---|
| 32" | 27.9 | 15.7 | 70.8 | 39.9 |
| 43" | 37.5 | 21.1 | 95.3 | 53.6 |
| 50" | 43.6 | 24.5 | 110.7 | 62.3 |
| 55" | 47.9 | 27.0 | 121.7 | 68.6 |
| 65" | 56.7 | 31.9 | 143.9 | 81.0 |
| 75" | 65.4 | 36.8 | 166.1 | 93.5 |
| 85" | 74.1 | 41.7 | 188.2 | 105.9 |
Math behind it: Using Pythagorean theorem with a 16:9 ratio.
The thing to watch is that TVs are sold by their diagonal alone, which hides how big the screen actually is. A 50-inch TV is about 43.6 inches wide, not 50, and that’s before the stand or bezel. It also means the jump between sizes is bigger than the numbers suggest: moving from a 55-inch to a 65-inch isn’t a 10-inch upgrade in area, it’s roughly 40 percent more screen, because area grows with the square of the diagonal.
This matters for two practical things. First, whether the set physically fits your stand or wall, so measure the width and height, not the diagonal. Second, how far back to sit: a common rule of thumb puts the comfortable viewing distance for a 4K TV at around 1 to 1.5 times the diagonal.
How we build and check this converter
This converter runs entirely in your browser, so the numbers you enter stay on your device. The math behind it is written by hand and tested against worked examples and standard references before the page goes live.
SuperGlobalCalculator is independently built and maintained. See how we build and verify our calculators.