About
THX recommends 36° viewing angle (cinema-like immersion). Casual TV viewing: smaller angle, sit further. Monitor: closer. Calculate by screen diagonal × multiplier. Too close = eye strain; too far = wasted resolution.
What is Optimal Screen Distance?
A Optimal Screen Distance computes optimal screen distance from the inputs you provide. It applies the standard formula to the values you enter and returns the result instantly, without sending any data to a server. Free Optimal Screen Distance. The.
Optimal Screen Distance
THX: 36° FOV. Sit 1.5× to 2.5× screen diagonal away.
Inputs
inches
Recommended Distance
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Breakdown
Min distance
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Max distance
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THX optimal
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Note
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About optimal screen distance
The best distance to sit from a screen is a balance between two competing goals: filling enough of your field of view to feel immersed, and staying far enough back that you cannot see individual pixels or strain to take in the whole image. Sit too close to a large TV and your eyes dart around to follow the action and the picture can look grainy; sit too far and a big, high-resolution panel is wasted because it no longer fills your vision.
The industry has two reference points. The THX standard targets a 36-degree horizontal viewing angle, the angle the screen subtends from your seat, which produces a cinema-like, immersive image. The older SMPTE guideline suggests a minimum of 30 degrees for a more relaxed home-theatre feel. Because a screen's diagonal and its width have a fixed relationship for 16:9 displays, both angles translate directly into a simple multiple of the screen's diagonal.
This calculator takes your screen diagonal and intended use (TV, monitor, or immersive) and returns a recommended distance, a comfortable minimum and maximum, and the THX-optimal seat, all in both inches and metres.
How the calculation works
Viewing distance is a multiple of the screen diagonal, with the multiplier chosen to hit a target viewing angle:
distance = diagonal x multiplier THX optimal = diagonal x 1.2 (about a 36-degree angle) TV / mixed = diagonal x 1.5 to 2.5 Monitor (desk) = diagonal x 1.0 to 1.5 Viewing angle = 2 x arctan( (screen_width / 2) / distance )
- Diagonal is the advertised screen size (the corner-to-corner measurement in inches).
- Multiplier shrinks for immersion (closer) and grows for a relaxed living-room feel (farther).
- Viewing angle is what actually matters; the multiplier is just a convenient proxy for a 16:9 panel.
- Resolution sets how close you can go before pixels show: 4K tolerates a much closer seat than 1080p.
Worked example
You have a 55-inch 4K TV and want a balanced living-room setup (not maximum immersion).
- Comfortable minimum: 55 x 1.5 = 82.5 inches (about 2.1 metres).
- Comfortable maximum: 55 x 2.5 = 137.5 inches (about 3.5 metres).
- Midpoint recommendation: (82.5 + 137.5) / 2 = 110 inches (about 2.8 metres).
- THX immersive seat: 55 x 1.2 = 66 inches (about 1.7 metres), noticeably closer.
- 4K bonus: because the panel is 4K, even the 66-inch immersive seat will not show visible pixels.
Result: A relaxed seat is around 110 inches (2.8 m) from a 55-inch set. Move in to about 66 inches (1.7 m) for a THX-style cinematic feel; the 4K resolution keeps the picture sharp at that distance.
Reference: recommended TV distance by size
| Screen size | Mixed (1.5x to 2.5x) | THX immersive (1.2x) |
|---|---|---|
| 43 inch | 65 - 108 in (1.6 - 2.7 m) | 52 in (1.3 m) |
| 55 inch | 83 - 138 in (2.1 - 3.5 m) | 66 in (1.7 m) |
| 65 inch | 98 - 163 in (2.5 - 4.1 m) | 78 in (2.0 m) |
| 75 inch | 113 - 188 in (2.9 - 4.8 m) | 90 in (2.3 m) |
| 85 inch | 128 - 213 in (3.2 - 5.4 m) | 102 in (2.6 m) |
Ranges assume a 16:9 panel. Choose the closer end for movies and 4K content, the farther end for casual or 1080p viewing.
Common pitfalls
- Measuring distance from the wall, not the screen. Use the distance from your eyes to the front of the panel, not to the cabinet or wall behind it.
- Ignoring resolution. The same seat that looks crisp on a 4K TV can look soft on 1080p. If you sit close, a higher-resolution panel pays off; if you sit far, you may not notice the difference.
- Buying for the room you wish you had. An 85-inch TV in a room where you sit 8 feet away can be overwhelming. Match the size to the seat you actually have.
- Confusing TV and monitor guidance. A desk monitor follows ergonomic rules (arm's length, top at eye level), not cinema immersion angles. Do not place a monitor as far as a TV.
- Forgetting height and angle. The center of the screen should sit near eye level. A screen mounted too high forces neck strain regardless of horizontal distance.
Related tools
Frequently asked questions
How far should I sit from my TV?
For mixed TV and movie viewing, sit roughly 1.5 to 2.5 times the screen diagonal away. A 55-inch TV gives a comfortable range of about 82 to 137 inches (2.1 to 3.5 metres). For a more cinematic, immersive experience THX recommends a 36-degree viewing angle, which is closer, around 1.2 times the diagonal. Sit nearer if you want immersion, farther if you want a relaxed living-room feel.
What is the THX recommended viewing angle?
THX certification targets a 36-degree horizontal viewing angle for the back row of a cinema, with SMPTE suggesting at least 30 degrees. A 36-degree angle means the screen fills a large part of your field of view for an immersive experience. In practice that works out to a viewing distance of about 1.2 times the screen diagonal for a 16:9 display.
Does 4K let me sit closer than 1080p?
Yes. The higher the resolution, the closer you can sit before individual pixels become visible. At a normal 1080p TV distance you would see pixel structure, but 4K packs four times the pixels into the same panel, so you can move in to fill more of your field of view without the picture looking soft. This is why 4K rewards a closer seat or a bigger screen at the same distance.
How close is too close for eye strain?
There is no evidence that sitting close to a modern flat-panel TV damages your eyes, but sitting too close can cause temporary eye strain and fatigue because your eyes work harder to track a wide, bright field. The old one-screen-diagonal minimum is a reasonable comfort floor for a TV. For a desk monitor, an arm's length (about 20 to 40 inches) is the ergonomic guideline.
What distance is best for a computer monitor?
For a desk monitor, ergonomic guidance is to place the screen about an arm's length away, with the top of the display at or just below eye level. That usually lands near 1.0 to 1.5 times the diagonal for a typical 24 to 32-inch monitor. The goal is different from a TV: you want text crisp and the whole screen reachable by a small eye movement, not maximum immersion.