Screen PPI (Pixels Per Inch) Calculator
Screen PPI (Pixels Per Inch) Calculator
Enter a screen's horizontal and vertical resolution in pixels, plus its diagonal size in inches. This calculates the pixel density (PPI) — how sharp the display looks based on how tightly its pixels are packed.
PPI is computed from the diagonal pixel count (using the Pythagorean theorem on the width and height in pixels) divided by the physical diagonal size, which is why two screens with the same resolution can have very different sharpness if their physical size differs. Smartphones, viewed up close, typically run 300-460+ PPI to stay sharp at close reading distance, while desktop monitors — viewed from further away — commonly sit around 90-110 PPI and still look crisp, which is a useful reference point when comparing whether a given resolution-and-size combination will actually look sharp for its intended viewing distance.
- Formula: PPI = √(Width² + Height²) ÷ Diagonal Size — the diagonal pixel count divided by the physical diagonal size.
- Higher PPI means sharper: smartphones typically run 300–460+ PPI (viewed up close), while desktop monitors are often 90–110 PPI (viewed from further away) and still look sharp.
- Why it matters: PPI helps compare display sharpness fairly across devices with very different sizes and resolutions — a 4K TV and a 4K phone have the same resolution but wildly different PPI.
What PPI counts as "Retina" quality?
Apple popularized the term for displays where individual pixels aren't distinguishable at a normal viewing distance — roughly 300+ PPI for phones held close, or around 220+ PPI for laptops viewed further away.
Does higher PPI always mean a better screen?
Not necessarily — PPI measures sharpness only; color accuracy, brightness, contrast, and refresh rate all matter too, and PPI gains become imperceptible well before infinity since the human eye has a resolution limit.
Screen PPI (Pixels Per Inch) Calculator
Enter a screen's horizontal and vertical resolution in pixels, plus its diagonal size in inches. This calculates the pixel density (PPI) — how sharp the display looks based on how tightly its pixels are packed.
PPI is computed from the diagonal pixel count (using the Pythagorean theorem on the width and height in pixels) divided by the physical diagonal size, which is why two screens with the same resolution can have very different sharpness if their physical size differs. Smartphones, viewed up close, typically run 300-460+ PPI to stay sharp at close reading distance, while desktop monitors — viewed from further away — commonly sit around 90-110 PPI and still look crisp, which is a useful reference point when comparing whether a given resolution-and-size combination will actually look sharp for its intended viewing distance.
- Formula: PPI = √(Width² + Height²) ÷ Diagonal Size — the diagonal pixel count divided by the physical diagonal size.
- Higher PPI means sharper: smartphones typically run 300–460+ PPI (viewed up close), while desktop monitors are often 90–110 PPI (viewed from further away) and still look sharp.
- Why it matters: PPI helps compare display sharpness fairly across devices with very different sizes and resolutions — a 4K TV and a 4K phone have the same resolution but wildly different PPI.
What PPI counts as "Retina" quality?
Apple popularized the term for displays where individual pixels aren't distinguishable at a normal viewing distance — roughly 300+ PPI for phones held close, or around 220+ PPI for laptops viewed further away.
Does higher PPI always mean a better screen?
Not necessarily — PPI measures sharpness only; color accuracy, brightness, contrast, and refresh rate all matter too, and PPI gains become imperceptible well before infinity since the human eye has a resolution limit.