Screen PPI Calculator
Enter a screen's pixel resolution and diagonal size to calculate its pixels per inch (PPI).
Last updated: September 5, 2026
Frequently asked questions
What is PPI?
Pixels per inch - a measure of screen pixel density. Higher PPI means individual pixels are smaller and harder to see, producing a sharper image at a given viewing distance.
What is the PPI of a 1920×1080 24-inch monitor?
About 91.79 PPI - the diagonal resolution is √(1920² + 1080²) ≈ 2203.1 pixels, divided by the 24-inch diagonal screen size.
Why does PPI matter for choosing a monitor or phone?
Higher PPI generally produces a sharper, more detailed image, but the difference becomes less noticeable the farther away you sit - phones (viewed close-up) benefit more from very high PPI than a TV (viewed from across a room).
What's the difference between PPI and DPI?
PPI (pixels per inch) describes screen or digital image resolution. DPI (dots per inch) technically refers to physical printer output resolution, though the terms are often used interchangeably in casual conversation.
What is the PPI of a typical smartphone screen, like 1080×2400 at 6.1 inches?
About 442 PPI - the diagonal resolution is √(1080² + 2400²) ≈ 2632.6 pixels, divided by the 6.1-inch diagonal. That's why phone screens look noticeably sharper up close than a monitor with a much lower PPI.
Does a higher-resolution screen always have a higher PPI?
Not necessarily - PPI depends on both resolution and physical size. A 4K (3840×2160) 43-inch TV has a lower PPI (~102) than a 1080p (1920×1080) 24-inch monitor (~92 is close, but a 15-inch 1080p laptop hits ~147 PPI) because the same pixel count is spread over more or less physical space.
Is PPI the same as 'Retina' display quality?
Not exactly - Apple's 'Retina' marketing term refers to a PPI high enough that individual pixels become imperceptible at a typical viewing distance for that device (roughly 300 PPI for phones held close, lower for monitors viewed farther away), not a fixed PPI number across all screen types.