Screen Distance Optimizer
The scientific way to choose your next screen size.
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What this calculator does
The Screen Distance Optimizer tells you what size TV or projector screen suits the distance you sit from it. Choose your screen's resolution and your viewing distance, and it shows a "cinematic sweet spot" size and a recommended range around it. Sizes are diagonal, in inches, the way TVs are sold.
How to use it
- Choose 4K (Ultra HD) or 1080p (Full HD).
- Measure from your eyes, sitting in your usual seat, to where the screen will be, and set the slider (3 to 15 feet).
- Read the sweet spot size and the recommended range. TVs come in fixed sizes (such as 55, 65, 75, 77, 83 and 85 inches), so pick the nearest size inside the range.
How it's calculated
The tool divides your distance in inches by a factor that depends on the resolution:
screen size (in) = distance (in) ÷ factor
| Resolution | Sweet spot | Range | Share of your view |
|---|---|---|---|
| 4K | distance ÷ 1.2 | ÷ 1.5 to ÷ 0.9 | about 40° (range 32°–52°) |
| 1080p | distance ÷ 1.6 | ÷ 2.2 to ÷ 1.3 | about 30° (range 22°–37°) |
Where the numbers come from
Two industry guidelines describe how much of your field of view a screen should fill:
- SMPTE, the film and television engineering society, recommends that the screen fill at least 30° of your horizontal view. On a 16:9 screen, that means sitting about 1.6 times the diagonal away.
- THX recommends about 40° for a cinema-like experience, which means sitting about 1.2 times the diagonal away.
Resolution decides how close you can sit before you see individual pixels. A person with 20/20 vision stops seeing 1080p pixels at about 1.6 times the screen's diagonal, so 1080p is matched to SMPTE's 30°. A 4K screen has twice the detail in each direction, so its pixels stay invisible down to about 0.8 times the diagonal. That makes THX's wider 40° practical, and even the top of the 4K range stays sharp.
A worked example
You sit 8 feet (96 inches) from the screen:
- 4K: 96 ÷ 1.2 = 80 inches sweet spot, with a range of 64 to 107 inches. A 75 or 77 inch TV is the nearest common size.
- 1080p: 96 ÷ 1.6 = 60 inches sweet spot, with a range of 44 to 74 inches. A 55 or 65 inch TV fits.
Tips for setting up
- Height: put the middle of the screen at about eye level from your seat. Tilting your head back to watch a TV mounted high over a fireplace strains your neck.
- Bigger isn't always better: near the top of the range you'll turn your eyes, or your head, to follow action at the edges. That's great for films and games, but tiring for news and everyday TV.
- Metric: 1 foot is 0.3048 m, so 2.5 m is about 8.2 feet. Multiply a size in inches by 2.54 for centimeters.
At a desk: computer monitors
The TV guidelines above don't apply to computer screens, which you sit much closer to. The American Academy of Ophthalmology recommends:
- Sit about 25 inches (an arm's length) from the screen.
- Place the screen so you look slightly down at it, not straight ahead or up.
- Follow the 20-20-20 rule: every 20 minutes, look at something at least 20 feet away for at least 20 seconds. This relaxes the eye's focusing muscles and helps prevent eye strain.
Frequently asked questions
Does this work for projectors?
Yes. The viewing angles are the same; use the diagonal of the projected image.
What about 8K?
8K pixels stay invisible even closer, but the comfort limit is your field of view, not the pixels. The 4K numbers are a good guide for 8K too.
My TV is a different shape. Does that matter?
The factors assume a standard 16:9 screen. An ultra-wide 21:9 screen with the same diagonal is wider, so it fills more of your view; choose a slightly smaller diagonal for the same effect.
Sources: SMPTE and THX viewing-angle recommendations, as summarized in Kaleidescape's Screen Size, Viewing Distance & Resolution guide; American Academy of Ophthalmology, Computers, Digital Devices, and Eye Strain. Last reviewed on SuiteWebTools: October 2026.