Sixty pixels per degree is where pixels vanish

20/20 vision resolves one arcminute, and a degree holds 60 of them — so about 60 pixels per degree is the point where a pixel grid stops being visible. Past it, more resolution changes nothing you can see.

Why it works

PPD depends on distance as much as on the panel, so sitting back doubles it just as surely as doubling the pixel count. It is why a 55-inch 1080p screen at 8 feet already reaches 67 PPD, and the 4K version of the same screen looks identical from that sofa.

Do it exactly

Estimate with the rule, then check it against the calculator that models it properly.

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How far should I sit from my TV?

20/20 vision resolves one arcminute, and a degree holds 60 of them — so about 60 pixels per degree is the point where a pixel grid stops being visible. Past it, more resolution changes nothing you can see. PPD depends on distance as much as on the panel, so sitting back doubles it just as surely as doubling the pixel count.

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