What is a good PPI for a monitor?

There isn't one universal answer, because PPI alone doesn't tell you what reaches your eye — that depends on how far you sit. A 27 inch 1440p monitor (108.8 PPI) at a typical 60 cm desk distance gives about 45 pixels per degree; a 27 inch 4K monitor (163.2 PPI) at the same distance gives about 67. Both are usable; the 4K panel is meaningfully sharper at that specific distance, and would still be if you sat further back.

What is PPD and how do I calculate it?

PPD, pixels per degree, is how many pixels fall within one degree of your visual field — PPI adjusted for viewing distance. The formula is PPD = PPI × distance in inches ÷ 57.2958 (the radian-to-degree constant). A 27 inch 4K monitor's 163.2 PPI at 60 cm (23.6 in) works out to roughly 67 PPD.

At what PPI can you not see pixels?

There's no fixed PPI threshold on its own — it depends on distance, which is exactly what PPD accounts for. The commonly used benchmark is about 60 pixels per degree, based on 20/20 vision resolving roughly one arcminute; above that, most people stop distinguishing individual pixels at normal viewing distances. Sharper eyesight or a high-contrast test pattern can push the practical threshold higher, so treat 60 as a reasonable line, not a hard cliff.

Is PPI the same as DPI?

No, though the terms get used interchangeably. DPI, dots per inch, is a printing term describing ink dots. PPI, pixels per inch, describes a display's actual pixel grid. A screen has no dots to count — it has pixels — so PPI is the correct term for a monitor or TV, even though DPI shows up constantly in casual use.

Does PPI matter at TV distances?

Less than you'd expect, and less than it matters on a monitor. Because TVs are viewed from much further away than their PPI figure implies, a 65 inch 4K TV's comparatively low 67.8 PPI still delivers more pixels per degree at a normal sofa distance than a much higher-PPI monitor does at a desk. Distance, not the panel spec, ends up doing most of the work.

Guide

PPI vs PPD: the number that actually matters

Updated 6 September 2026

A 65 inch 4K TV has 67.8 PPI. A 27 inch 4K monitor has 163.2 — more than double. And yet from where you actually sit, the TV delivers 116 pixels per degree to your eye, and the monitor only 67. PPI describes the panel. It says nothing about the distance between that panel and you, which is exactly the gap pixels-per-degree closes.

PPI, in one formula

PPI = √(pixels wide² + pixels tall²) ÷ diagonal (inches). A 27 inch monitor at 2560×1440: √(2560² + 1440²) = 2937.2, divided by 27 inches gives 108.8 PPI. This is a fixed property of the panel — it never changes with where you put it.

PPD, in one more

PPD = PPI × distance (inches) ÷ 57.2958 — that constant converts radians to degrees, since a "pixel per degree" is fundamentally an angular measurement, not a linear one. Sit that same 108.8 PPI monitor 60 cm (23.6 in) away: 108.8 × 23.6 ÷ 57.2958 works out to 44.9 pixels per degree. Move it further away and the same panel delivers more PPD, because each pixel now covers a smaller slice of your field of view. PPI is fixed; PPD moves every time you do.

The 60 PPD line

20/20 vision resolves roughly one arcminute of detail — a sixtieth of a degree — so about 60 pixels per degree is where a pixel grid stops being individually resolvable to a typical eye. It's a genuinely useful benchmark, not a hard cliff: sharper-than-20/20 eyesight, or a high-contrast test pattern designed to expose pixel edges, can push the practical threshold higher for some viewers. Treat 60 as "comfortably past this and pixel structure is very unlikely to be visible," not as an exact line nobody could ever cross.

The comparison table nobody publishes

Screen	PPI	Typical distance	PPD
Phone, 6.1 in	457.2	30 cm	94
Monitor, 27 in 1440p	108.8	60 cm	45
Monitor, 27 in 4K	163.2	60 cm	67
Monitor, 32 in 4K	137.7	70 cm	66
TV, 55 in 4K	80.1	2.5 m	138
TV, 65 in 4K	67.8	2.5 m	116
TV, 85 in 4K	51.8	3.0 m	107
TV, 65 in 8K	135.6	2.5 m	233

The ordering is the entire point. The 27 inch 4K monitor has nearly triple the PPI of the 65 inch 4K TV — and delivers roughly half the PPD, because the TV sits so much further away. PPI ranks panels. PPD ranks what actually reaches your eye, and those two rankings don't agree.

Which is why 8K is a solved argument

A 65 inch 8K panel at a normal 2.5 m sofa distance works out to 233 pixels per degree — nearly four times the roughly-60 threshold above. Doubling the resolution again from there buys pixel density nobody's eye can use at that distance. This isn't a matter of taste or of one brand's marketing claim; it falls straight out of the same formula as every row in the table above.

The distance-per-inch shortcut

The same maths simplifies to a rule you can use without a calculator: on a 4K panel you stop resolving individual pixels at roughly 2 cm of distance for every inch of diagonal — 3 cm on 1440p, 4 cm on 1080p, 1 cm on 8K. A 27 inch 1440p monitor needs about 80 cm; a 27 inch 4K needs about 54 cm; a 65 inch 4K TV needs about 1.29 m. Sit further than that and resolution has already stopped being the constraint, whatever the spec sheet says.

PPI vs DPI

DPI — dots per inch — is a printing term, describing ink dots laid down on paper. PPI — pixels per inch — describes an actual pixel grid on a screen. There are no dots on a display to count, only pixels, so PPI is the technically correct term for a monitor or TV. The two get used interchangeably in casual conversation and even in some spec sheets, but they're not describing the same physical thing.

Where PPI still wins

PPD assumes you never lean in, and plenty of real use — reading fine print, zooming into a photo, close design work — involves leaning closer than your "typical" distance. Text rendering, font hinting and subpixel layout are all governed by the panel's actual pixel grid, not by how far away you happen to be sitting at any given moment. Scaling behaviour in an operating system is also a PPI problem specifically: a high-PPI panel needs OS-level scaling to keep text a readable physical size, regardless of how many pixels per degree it delivers from across the room.

See your own resolution and PPI, or check a specific monitor's dimensions and a 65 inch TV's to run these numbers for your own setup.

On a 120 cm × 60 cm desk at 65 cm, the strongest match is a 27 inch monitor. Open the calculator to use your own measurements.

Common questions

What is a good PPI for a monitor?: There isn't one universal answer, because PPI alone doesn't tell you what reaches your eye — that depends on how far you sit. A 27 inch 1440p monitor (108.8 PPI) at a typical 60 cm desk distance gives about 45 pixels per degree; a 27 inch 4K monitor (163.2 PPI) at the same distance gives about 67. Both are usable; the 4K panel is meaningfully sharper at that specific distance, and would still be if you sat further back.
What is PPD and how do I calculate it?: PPD, pixels per degree, is how many pixels fall within one degree of your visual field — PPI adjusted for viewing distance. The formula is PPD = PPI × distance in inches ÷ 57.2958 (the radian-to-degree constant). A 27 inch 4K monitor's 163.2 PPI at 60 cm (23.6 in) works out to roughly 67 PPD.
At what PPI can you not see pixels?: There's no fixed PPI threshold on its own — it depends on distance, which is exactly what PPD accounts for. The commonly used benchmark is about 60 pixels per degree, based on 20/20 vision resolving roughly one arcminute; above that, most people stop distinguishing individual pixels at normal viewing distances. Sharper eyesight or a high-contrast test pattern can push the practical threshold higher, so treat 60 as a reasonable line, not a hard cliff.
Is PPI the same as DPI?: No, though the terms get used interchangeably. DPI, dots per inch, is a printing term describing ink dots. PPI, pixels per inch, describes a display's actual pixel grid. A screen has no dots to count — it has pixels — so PPI is the correct term for a monitor or TV, even though DPI shows up constantly in casual use.
Does PPI matter at TV distances?: Less than you'd expect, and less than it matters on a monitor. Because TVs are viewed from much further away than their PPI figure implies, a 65 inch 4K TV's comparatively low 67.8 PPI still delivers more pixels per degree at a normal sofa distance than a much higher-PPI monitor does at a desk. Distance, not the panel spec, ends up doing most of the work.